MR2-FA: Shaping Metal

One of the first skills I started practicing when I got serious about preparing for this project is metal shaping.  I haven't posted anything I've done yet because honestly it's all just been a bunch of experiments that went into the trash afterwards but once I start doing serious work for the car you'll get a chance to see those.

People will tell you that it's a requirement that you have an English Wheel, pneumatic planishing hammer, and blah blah blah in order to make a body panel correctly.  Those people have no imagination.  Do those tools make shaping metal easier?  Absolutely.  Are they an absolute requirement for doing any metalwork?  No. Not even remotely. What you need are proper instruction, hand tools, and practice.

If you think about it for more than ten seconds and you have any sense of history you'll realize that metal has been bent into all sorts of interesting and beautiful shapes for CENTURIES prior to any of those tools existing.  How? Heat, and a hammer.  That's it. 

I'm not usually one to plug things for other people unless I really feel strongly about it.  That said, here's someone doing work that deserves people's money:

www.metalshapingzone.com

When I started looking around for tutorials on how to do what I wanted to do I found this guys site and bought his video.  Buy a copy if you're even remotely interested in body work.  

MR2-FA: What makes an MR2 an MR2?

Invairably in any styling exercise where you're bringing forward or abandoning some elements of the cars from the past you're going to create critics.  First off I'll say that I'm not doing this because I don't like the SW20 MR2 - in fact the opposite is true.  I'm doing this project precisely because I like the SW20 MR2 and it's predicessor the AW10/11.  The MR2 Sypder was a styling abortion and I absolutely can't stand looking at it so we're going to pretend that it never existed for the purposes of designing my car.

I've done a lot of analysis on Lexus familial and performance styling elements but till now I haven't posted anything about MR2 specific styling elements.  That was on purpose, because I had been thinking about it a lot and it's a bit of a complicated issue.  For most people if you look at the original MR2 and SW20 there's only a few things that you'd notice that they have in common and would think - without applying any addittional logic - would make sense to pull forward.

The common styling elements (front to back):

1. Pop up headlights

2. T-top roof (as an option)

3. Air vents behind the doors (on most models)

4. Notch back engine lid/rear

5. Dual exhausts

As far as model carryovers, that's not a lot.  The AW11 MR2 is boxy, and the SW20 is round.  Other than the number of seats and where the engine is there's not a lot other than make and model name that tie the two together visually. Now you have to ask yourself - which of these make sense in a modern car?  Let's take them one at a time:

1. Pop up headlights: These are a relic from a bygone era when you couldn't have a small headlamp and decent light output because the world lacked cost-effective projectors and HID's.  There's no way a modern car would have these so they're out. 

2. T-Top roof:  These just don't get made anymore because car companies have figured out how to make convertible roof's that don't suck.  They've also figured out how to build in enough chassis rigidity that you don't have to worry about ruining the structure of the car by taking off the roof.   Removing T-tops is also a pain in the ass.  However, I like them so they stay.  There's something throwback-cool about them like old-skool jerseys or boom boxes.  They're 80's fabulous. 

3. Air vents behind the doors:  These are basically a functional requirement more than a styling element and we've already established that they exist on modern cars, including the LFA, so they stay.

4. Notch back engine lid/rear:  Now here's where I piss off the purists.  One of the design elements that I'm insistent on for project MR2-FA is a fastback style engine lid.  Neither the AW11 or SW20 were fastbacks.  The fact that I refuse to do a notchback is likely to be deemed as herasy but there's a good reason for it.  It's what Toyota would do.  Hear me out.

Notchbacks aren't great for aerodynamics.  They create a low pressure zone above the engine lid that leads to all sorts of detrimental effects.  Did Toyota just not know that in the 80's? Actually I'm going to say they probably did.  So why did they go with a notchback then?  Because that's what Ferrari was doing at the time.  I'm not going to link to it, but if you look up the models that Ferrari was producing during the MR2's production run you'll see that all the mid-engine cars are  notchbacks with only one exception (the F40).  The SW20 MR2 was meant to offer mini-ferrari styling at a price point that a common person could afford.  To this day you can still get Ferrari style converions that will make your pedestrian Japanese sports car look just like high dollar sheet metal from Italy. 

If you buy into that idea here's another one.  Ferrari doesn't do notchbacks anymore and haven't for years.  Why? Who cares.  The point is that they don't, therefore if the MR2 were to maintain the Ferrari influence into modern times it would do so with a piece of glass over the engine.  You can say what you want about my decision, but the logic is solid.  Which leaves us with...

5. Dual Exhausts.  Given that I've got a V6 on an engine stand waiting to be transplanted this is almost a requirement.  I could probably get away with a single 2.5" pipe all the way back, but I think those look stupid so we're sticking wtih dual exhaust tips.  Where they're located is a diffferent story. 

So, of the five elements that really define what an MR2 looks like, the only things I really need to keep are the T-tops, the air vents, and the dual exhausts.  Everything else - assuming I weren't to do something assenine like add a rear seat - is pretty much fair game.  Disagree if you like, hate on it if you must, but the fact is there isn't a lot of model specific styling that I need to bring forward.  This means that I'm free to build whatever I want within reason.  I like that.

MR2-FA: Photoshop Contest

I can't draw for crap.  This is a little sad for me as I used to draw comic books in High School.  The problem is that was 15 years ago and I've got exactly zero interesting in putting in the time to become good enough to do what I need for this project.  I'd rather be welding.

The photoshop contest that recently ended was specifically designed to help me find exactly what I ended up finding: a young-ish person that likes cars, has mad skill and some time to kill, and is still malleable enough that they won't try and ram their own ideas down my throat. 

And the winner is...the nice young man who drew these:

Welcome to the team laddie.  It's going to be fun. 

MR2-FA: The (Base) Model - Part 1

Before you go trying to build out a full scale version of a car it's typically a good idea to build out a scale model first.  You see this all the time if you watch car magazines.  There will be a lump of clay on a pedestal, then a couple shots later you see a finished clay shape.  Since I'm not building a car completely from scratch, but rather re-designing an already existing chassis, I've got a few more options that someone with just a lump of clay wouldn't have, namely that I can find a scale model the right size and start there.

I searched around and with a little help was able to find this:

It's a 10:1 RC car that's an exact scale model of the SW20 MR2.  10:1 is the perfect size for this if you don't have the ability to make something full size because any measurements on the base model or the car only need to be divided by or multiplied by 10 to get the corresponding line on whatever you're building.  Obviously I could just cut this up and run with it but I didn't because it would have been a wasted opportunity and I'd only get one shot at it.  If I cut up a line I later wanted back, I'd be screwed.  I could probably make it work, but it'd be a lot more painful than it needs to be. 

I decided instead to teach myself a new process - creating a resin reinforced latex mold.  I haven't done this before, but it's a pretty useful skill with a lot of potential applications so I was willing to spend the $80 in materials required to figure it out.  Latex as a material has some nice properties, and some tricky properties.  First off, the base latex and the hardener need to be measured precisely.  Luckily I've got scales for just such occasions - here we've got 300 grams of the base measured out.  When I'm working I almost always work in metric because way more precise than using U.S. measurements. 

Second - when you mix the stuff it introduces air pockets that you need to remove.  There's two ways to do this - 1) a vaccume pump 2)"Bombs Away".  I have a vacuume pump but it's not setup right for doing this and it'd take to long to get it there so I went with bombs away which is basicall just slowly pouring the mixed latex from one cup into another from three feet or higher away.  It's messy - but it worked. 

I didn't get this process right on this - my first - go but I learned what I needed to in order to be able to do the job right when I make the final mold of whatever the finished shape of my car is going to be.  In the interest of posterity I'll take you through that now. 

1. Secure the model to a base.  In this case I used a free (thanks Tap Plastics!) piece of acrylic sheet that they gave me when I got the molding supplies.

2. Mix up a precise amount of Latex according to the directions.  For this first pass - don't mix up very much. 

3. Do a thin layer over the model.  I applied this using the same process I use for wetting out chop mat which is called stippling.  You use the brush to jab the material into all the crevaces and make sure you pick up the surface detail.  Once I had the whole thing covered I brushed on a bit more.  I forgot to take a picture though.  Sorry. 

4. Wait until the first layer is tacky, meaning it's sticky to the touch but doesn't come off on your fingertip and then do a second, and thicker coating.  I did remember to take a picture of my second layer:

5. Keep going till you get the mold the thickness you need.  I was aiming for 1/4 inch, but I missed the mark in a few spots.  More on this later.

6. When you're absolutely certain you've got all the details picked up (for me this was after two layers) mix up another batch of silicon but this time add a thixotropic additive.  Thixhotropic is a fancy way to say thickening agent.  I found it makes the silicon more like a paste and you need to trowel it on rather than brush it.  Here we've got the third layer.  Looks kinda like a cake:

I could have and should have taken the time to get this smoother, but I had to go change a diaper on my daughter so I had to live with it. 

That's pretty much it for the latex part.  The next part is actually just adding fiberglass over the top of it so that the latex keeps its shape when you're popping out parts. For this I decided to use a couple of materials I mentioned in my post about materials. 

1. I did a layer of resin with Cab-o-Sil.  I like this stuff, but you better wear a dust mask.  I did, but just the small amount that got on my clothes proved to me that it's not a material to be taken lightly.  Eye protection is an abolute requirement when messing with this stuff.  You can see that it turns the resin into sort of a paste:

I then spread this over the model and the wooden trim I put together for it. 

2. Once that started to tack up, I did a second layer but this time I added microspheres to help bulk out the resin so I didn't need to burn through as much.  I like this product too.  It bulks out the resin but doesn't change the viscosity so you could still pour it or wet out chop mat with it the same as if it was just resin.  As with the Cab-o-sil, this stuff works great but it's nasty so a respirator and goggles are a requirement.  Here we are after a layer of the new Cab-o-sil and microspheres resin mix:

3. I did one more layer with this mixture:

 

 I then did a single layer of chop mat over this with just regular resin with the surface curing agent:

So how did I do?  Honestly I only did OK.  I thought at first I could use the mold but on further reflection I'm better off just trying to make another one.  What did I do wrong and right?

Wrong:  I was trying to be a bit stingy with the silicon because I wanted to save a bunch for the finished MR2-FA model and didn't want to buy more.  Now I'm going to have to buy more anyway because I need to make another mold.  The key point is - make the silicon thick.  Like maybe 3/4 of an inch.  You want the mold to hold it's basic overall shape without the fiberglass.  The fiberglass is just to make absolutely sure nothing moves or shifts.

Right:  I got all the detail of the original piece and there were no air bubbles so my method of application worked, and worked well. 

Overall it was a fun process and I'm glad I took the time to try it.  All my mistakes are easy to fix and the experience was well worth it for when I make the second SW20 mold and the final mold of MR2-FA.  

Tip 4: Making Your Own Gauge Locations

Here's another question that comes up a lot so it's time for Tip 4.

Ok after seeing your center console with t gauges mounted above the cd player i almost died.I love it.I want it. I have to have it.  How do I do it?

Both my WRX and my MR2 came with dual din CD/Tape decks that take up twice the space of a new deck you'd buy.  Usually when you buy a deck the seller also tries to get you to buy an "install kit" which consists of a bracket and a pocket to take up the space that the original deck has just vacated.  The problem with these pockets is they're utterly useless as anything you put in there is going to come flying out the first time you hit the brakes with any meaningful force.

So rather than stick the pocket in like everybody else, I actually smoothed over the location and made a gauge mounting location.



The trick to this is a little bit of backyard engineering using unorthodox materials.  The problem with filling in a location like that is there's a 90 degree bend.  It's suprisingly hard to find plastic pieces that aren't part of something else you wouldn't want to ruin that also contain a 90 degree bend.  The solution comes from your local hardware store.  Walk in, and ask where to find these:

http://www.homedepot.com/h_d1/N-5yc1vZ1xh8/R-100318664/h_d2/ProductDisplay?langId=-1&storeId=10051&catalogId=10053

They're gass blocks you sometimes see in bathrooms.  Somewhere in that section of the store (I can't find a link to the actual product online for some reason) you'll find a piece of plastic that looks like this:



This is a bracket that you use to mount those glass blocks to the floor or wherever you're putting them. As you can see it's got a 90 degree bend.  It's also got a line down the middle that inexplicably is almost exactly the same size as the slot you need to fill in.  What you do from here is measure the location you want to fill, cut a piece to length, take down the edges, and glue it in place. 

As far as gluing it in place there's two things:

1. Reinforce the area. Well.  If you haven't pre-drilled your gauge holes, and I'd actually recommend that you not because drilling through it will tell you if you made it sturdy enough, you need something behind the piece you cut to actually connect it with the mounting surface.

What I do is get the piece that'll be on the front exactly the right size to fit the location I want to fill in first. 



Then I cut off a slightly larger piece for the back side and take off the 90 degree portion with a dremel and a cutoff wheel.



2. For glue I use a product category called "Plastic Weld".   I tried regular epoxy first because I have tons of it, but it didn't work.  I was walking through the auto parts store and found "Plastic Weld Epoxy" in the aisle that had RTV Silicon and such.  This worked much better.  It works better than epoxy on plastic because first off it's specifically designed for that job and it also has some flex to it just like the plastic pieces you're gluing together.   That way when the piece flexes (like when you're actually putting in your gauges) the thing won't crack. 

You will invariably need to fill in the gap between the piece you glued in and the location you're mounting it to.  You'll also want to fill in any minor scratches or imperfections on the plastic.  For that see Tip 1.  I just use the same bumper filler stuff I go over in detail in that post. 

MR2-FA: Additional Project Considerations

I've done plenty of analysis so far but I've got a lot more on my mind that doesn't fit neatly into a single topic so this is my post with random things I'm either thinking about or need to take into consideration when designing the exterior of the MR2. 

Polar Moiment of Inertia
The technical definition of this is the resistance of an object to rotational acceleration.  The practical application is putting more weight past the wheel base on either end of the car affects weight transfer and therefore how the car corners.   You want as little mass past the wheelbase as possible ideally which creates a low polar moment of inertia.  The textbook example of this is the McLaren F1: there's almost nothing past the wheels. Despite being only 4.6 inches longer than the SW20 MR2 the wheelbase is 12.5 inches longer. In people terms that's the difference between having nice long sprinters legs or a torso the size of someone six inches taller than you. 

On the MR2 there's a lot of mass past the wheelbase on either side of the car.  In the back you've got the exhaust system, trunk, wing, tail lights, and bumper and in the front you've got the radiator, headlights, windshield washer tank, and front bumper.  I need to pull as much weight inwards, and low, as possible. 

Facilities
I obviously spend a lot of my free time working on making things. I also spend an inordinate amount of time cleaning up. Part of it is that I should work neater but a good chunk of it is purely based on the ameneties of my workspace or lack thereof. There's two locations in my house, other than my home office, that are my domain where I'm free to do as I wish: an unfinished room in my basement that we call "the junk room", and; the garage. There's a stipulation on the garage though, which is that at the end of my nightly activities my wife would really like her car parked inside.

A hobby like mine almost requires a house with a three car garage or at least a lot more space than I've got avaliable. I just don't have a lot of space to hold things that are in-process. I made some adjustments this week (I'm on vacation) to my workspace that I think will save some grief in the future.

After thinking through what was wrong with my previous garage setups it's that I didn't take into account the various states that a specific piece or part can be found in.   As a result I've setup my work areas like a factory; you have raw materials inventory, a WIP inventory, an assembly/construction floor, and a design studio.  This new level of organization should also speed up the process since I won't have to go rummaging around to find a specific material. 

Construction Order
If I gave you a pencil and a piece of paper and told you to draw a car where would you start?  How would you draw the rest?  In what order could you realistically figure out the proportions of things?  If you haven't done it before, you'd probably need a little bit of time to sort that out.  Given that I'm building and not drawing a car, I need to have this all thought through to some extent before I dive in or I'm going to end up with mismatched shapes and locations. 

I've thought about it quite a bit, and here's the order that I think makes sense with regards to builing each individual piece. 

1. Doors: This is going to be the most devilishly hard part of this entire exercise because it employs all the skills I have the least experience with.  Since the doors are the only OEM body piece that needs to remain essentially intact for safety, and also needs to be completely redesigned for asthetics, it makes sense to start there.

2. Mounting Brackets for Headlights:  All pieces on the front of the car need to fit around these so they need to be mounted good and sturdy or everything else will be off. 

3. Front Fenders: I want to get experience with the foam and molding before I go crazy building out a front bumper.  I can't make a mold for the fenders and get all the mounting tabs if the Bumper is in the way.  These and the doors sort of need to be designed together so there will probably be some overlap.

4. Front Bumper: The final line of the hood will need to be based on where the bumper terminates.  I'll need to relocate the radiator and build the ducting as part of this piece.

5. Hood:  The hood is the last piece on the front of the car and till the bumper and radiator relocation are done I won't know how it needs to be setup. 

6. Side Intake Vents: If you look at the LFA these flow into the side skirts.  Till I have them completed I won't know what the skirts need to be shaped like.

7. Side Skirts: Last piece on the side of the car and the one most independent of everything else in terms of when I would need to construct it.  Makes sense to do it last then move on to the rear. 

8. Fastback Engine Lid:  To me the entire rear of the car starts here.  Can I put hinges on?  Will I make it and the trunk lid all one piece?  I'll probably decide that as I go but regardless the design of the rear of the vehicle needs to start with this. 

9. Trunk Lid.  I won't know if the rear quarter panels need to be reshaped to match the lid and fastback until I get all those and the trunk lid finished.  

10. Rear Quarter Panels: Much like the doors, this needs to stay relatively intact for safety.  However, unlike the doors if I screw up I can't just go to a junk yard and find another to replace it.  By the time I'm ready to play with this area I should be pretty good at tack welding and metal shaping which will help minimize the possibility of my screwing up. 

11. Rear Bumper:  The rest of the car will be done by this point and it's the last thing left besides the part I must finish absolutely last.

12. Mirrors:  In order to put mirros in the right position, you need to make sure you can see around the rear of the car.  Till I know how wide the car is going to be it's pointless to finish the mirrors.

Tooling
I've seen a lot of automotive exterior projects while surfing over on Fiberglass Forums.  There's a couple of gaps that I see in most of the projects that I want to address for my own.  The biggest recurring problems that I see are: 1) wasted materials 2)inconsistencies between two sides of the vehicle 3) lack of consistent lines across complex parts.  There are plenty of good reasons why all of these occur but I think the solutions all boil down to the same thing: lack of tools. 

If you're just globbing on some foam and shaping things from there of course you're going to waste a ton of foam.  If all you've got is a basic ruler to check your measurements of course things are going to be off between two sides of the car.  I have some ideas about what it would take in terms of tools to fix all this stuff - the problem is I have to make them myself because as near as I can tell they don't actually exist.

Gauging Success

Aerodynamics and vehicle dynamics are black arts to your average car guy. Things don't work like exactly like you think they should and you'll have no idea unless you've actually tested it. The forces at play are just too complex for equations and assumptions to be your entire basis for decision making. For aero that means a wind tunnel and for vehicle dynamics that means a chassis jig, shock jig, and a lot of seat time. Any of those are way beyond the means of any normal person. I don't know the first thing about applying fluid dynamics, or about chassis tuning and the blance between regidity and crash worthiness, nor adjusting the valving on a shock to achieve certain ride frequencies. I'm stuck with common sense, books, and buying someone elses coilover system.

The good news and bad news is that since I'm making a road car and not a race car I can get away with pretty much anything. It's good because if I make a mistake it's unlikely it'll kill me. It's bad because it'll be hard for me to ever know if I did it right. I'm going to do my best to figure out ways to test things but I'm probably going to have to ask for some help to figure out how well I did.

25 Ways to Live Like a Car Guy

I've mentioned this in multiple posts, and it's going to be a recurring theme so I figured now was as good a time as any to actually type it up. If you've got a copy of the January 2006 Sport Compact Car you've already got this list but for some strange reason it's really hard to find it anywhere on the internet. Here is the original version from the magazine.

Original Version

1. Find uninterrupted driving.
2. Do your first track day.
3. Own a must have tool.
4. Test as many cars as possible.
5. Beat a speeding ticket.
6. Watch the sun set in LA and New York within two days and 3,000 miles.
7. Buy a beater.
8. Dyno your car.
9. Go to driving school.
10. Powerslide.
11. Learn to left-foot brake.
12. Do a Rockford. Well.
13. Rent a rear-whee-drive rental car and drive it like a rental car
14. Watch a local short-track race on Saturday Night
15. Go to a NASCAR race and experience the real action: the infield.
16. Volunteer for a weekend of pit crew duty in grassroots racing.
17. Taste every one of the 24 hours of Le Mans.
18. Four Words: Autobahn, Nurburgring, and Ring Taxi.
19. Race your car at the local grudge match drag races.
20. Wrench all night.
21. Drive an open-wheel car with downforce.
22. Buy the first car you fell in love with.
23. Drive on Route 66.
24. Modify your car the day before a 200-mile trip and find out just how much you really know about cars.
25. Jump your car.

I really like that list but some of the items I just don’t ever see myself doing or are wholly impractical given my living situation.   Here’s the stuff I pulled off and why:

4. Test as many cars as possible. – What the hell does this even mean anyway? How do you know when you’ve accomplished it?

6. Watch the sun set in L.A. and New York within two days and 3,000 miles. – I don’t live in New York or L.A. and taking a trip to either to drive to the other just isn’t worth the time or effort.

7. Buy a beater. – My first car was a beater. My second car was a beater. My third car was a beater. I’m not owning more.

14. Watch a local short-track race on Saturday Night – I have nothing against this one, I just needed the space.

15. Go to a NASCAR race and experience the real action: the infield. – No. Just…No. Are you serious!? I HATE NASCAR. No.

16. Volunteer for a weekend of pit crew duty in grassroots racing. – I like wrenching for me or friends who help me with wrenching.  I don’t like wrenching for anybody else - even my wife.  I’m not burning a weekend doing it for total strangers.

Here's my personal list with corresponding commentary. The original list had something like this but it's a lot of trouble to type it all up just for posterity so I added my own commentary for the items I've substituted in.

My Version 

1. Find uninterrupted driving. 
2. Do your first track day. 
3. Own a must have tool.
4. Weld your own exhaust.  Unobtainium exhausts from Japan are cool, light, and well designed.  They're also more expensive than hard drugs.  Constructing an exhaust of your own design using ghetto parts that still sounds awesome is a path to carmic and sonic liberation. 
5. Beat a speeding ticket. 
6. Swap an engine into a car it wasn't meant for.  Car companies make most of their small and light vehicles for regular people and as such install the smallest engine that will still allow the vehicle to merge with traffic on the freeway.  These engines are made from 100% suck.  Cramming a V8 into a car the size of a shoe is inherently difficult and time consuming but your reward is shedding the constraints of an economy motor and being able to do burnouts or donuts on comand. That's a prize worth going after for a real car guy. 
7. Boost a naturally aspirated engine.  Unlike the soldeirs in the Army your engine isn't being all it can be.  In fact it's probably being 70% of what it can be because someone worried about reliability decided it was a bad idea to put a turbo on an engine with a compression ratio of 10.5:1.  Reliability is for family sedans and if nothing ever goes wrong you can't knock off #14.  Boost it up.  Blow it up.  Rebuild it better and stronger. 
8. Dyno your car.
9. Go to driving school.
10. Powerslide.
11. Learn to left-foot brake.
12. Do a Rockford. Well.
13. Rent a rear-whee-drive rental car and drive it like a rental car. 
14. Rebuild an Engine.  There's nothing like taking something completely apart to really get intimate with how it works yet it's the rare car guy that's gone through the process of tearing down and building up a motor.  You need tools, skills, and money and if you do it wrong you'll need more of all three.  That's ok because you'll learn more through the process about motors than you ever could from a BGB.
15. Design a car.  Imagine a car driving past you on the freeway.  Now imagine that you penned every line, every crease, and every seam of that car.  Most of us will never know what that feels like but that doesn't have to stop you from achieving this.  Learn to draw and pen your own masterwork.  You may never get to see it in the flesh but it can still be a perfect incarnation of your own ideas about cars.
16. Destroy a car. Many people have done the "I swerved out of the path of a deer and hit a tree" destroyed.  This is the  "I took a sawzall to the roof" destroyed. It's sort of like cleaning a fish or game animal - dirty, gross, and rediculously interesting all at the same time.  It's also a great way to get out every frustration you've ever felt while working on a car.  Nothing says freedom like sawing through an A-pillar and pulling off a roof. 
17. Taste every one of the 24 hours of Le Mans.
18. Four Words: Autobahn, Nurburgring, and Ring Taxi.
19. Race your car at the local grudge match drag races.
20. Wrench all night.
21. Drive an open-wheel car with downforce.
22. Buy the first car you fell in love with.
23. Drive on Route 66.
24. Modify your car the day before a 200-mile trip and find out just how much you really know about cars.
25. Jump your car.

Here's my tally thus far:

1. Find uninterrupted driving.
2. Do your first track day.
3. Own a must have tool.
4. Weld your own exhaust.
5. Beat a speeding ticket.
6. Swap an engine into a car it wasn't meant for.
7. Boost a naturally aspirated engine.
8. Dyno your car.
9. Go to driving school.
10. Powerslide.
11. Learn to left-foot brake.
12. Do a Rockford. Well.
13. Rent a rear-whee-drive rental car and drive it like a rental car.
14. Rebuild an Engine.
15. Design a car.
16. Destroy a car.
17. Taste every one of the 24 hours of Le Mans.
18. Four Words: Autobahn, Nurburgring, and Ring Taxi.
19. Race your car at the local grudge match drag races.
20. Wrench all night.
21. Drive an open-wheel car with downforce.
22. Buy the first car you fell in love with.
23. Drive on Route 66.
24. Modify your car the day before a 200-mile trip and find out just how much you really know about cars.
25. Jump your car.

I'm currently at 11/25.  The plan is to use the MR2 and ES300 to cross off 4, 6, 7, 11, 12, 14, 15, 16 which will put me at 19/25. 

9 I'll do at some point well after the MR2 is finished and I've got a couple grand burning a hole in my pocket.  I don't think an autocross or track day class counts - I want to do a real school where you're using their cars.

I'll need to take a trip to Europe and not let my wife plan the whole thing to get 17 and 18. 

I have no idea how I'm going to get 21 but perhaps I can make that part of #9. 

23 is going to be a problem since Route 66 is pretty damn far away from me but I can make a special trip.  Maybe with my son when he's old enough.

25 - no idea.  I'll first need to get a car I wouldn't mind destroying while attempting it and weld in a roll cage.  Sounds like something to try with a gutted Subaru 2.5RS on rally tires.  Some day...

Tip 3: Materials

I get this question pretty regularly on every car forum I post on so rather than rewriting it seventeen time it's time for Tip 3:

Can you post some links to the products you use?  It'd be good to know what glues, paints, fillers, etc. I should be looking at buying.

There's some of this weaved into the previous two tips because you can't really talk about building something  without knowing what you'd use to do so, but I think a comprehensive list would be helpful for someone just starting out.  There's a couple of different categories to materials so we'll tackle them that way.  I'm going to use Amazon (usually not the best place to buy) and Tapp Plastics to provide links because between the two of them they've got everything I use regularly.  Yes, I know there are cheaper places to get my supplies than Tapp Plastics but the store I go to knows me, knows what I spend, and therefore takes care of me and kicks me freebies on a regular basis. That extra couple yards of fabric or free bottle of PVA adds up.  Sometimes it does pay to shop in your home town.

This is by no means an exhaustive list.  If you're trying to join two materials or fill something in a specific way and it's related to a car there's probably an "exact right" product to use.  I'm not a product reviewer so I'm just giving you the list of stuff I've actually tried or done enough research on to know whether or not it'll work.  The point of this is to help you get started.  You can get into exotic stuff on your own and report back to me when you've found the faults and applications.

Category 1: Fiberglass Resin

There are many different kinds of resin, what you choose to use is dependent on what you're trying to build and how big your budget is but in broad strokes there only two types: good stuff; and crap.  Good stuff is what you get from Tapp Plastics and US Composites.  Crap is what you get from your local hardware or autoparts store.  Here's the funny thing: they cost about the same.  No seriously - I've used enough of both to know.

One of the basic differences between the good stuff and the crap is the addition of wax.  There's a lot of it in the Elmers and Bondo brand resins.  At the end of the day you actually want some, but with the good stuff you typically need to add it yourself.  The advantage of adding wax yourself and at the time of your choosing is that it allows you to take more time betwen layers and control when the piece will start fully curing.  With the cheaper stuff it starts fully curing the second you add the hardener. 

So for example, let's say you're making a car hood which is a fairly big piece.  Let's further say that you add a couple of layers of resin in one go, but have to run out somewhere because you have a life.  Now you get the pleasure of sanding the entire piece down before you add any additional layers or they won't fully adhere.   I don't know about you but that sounds like a truely massive pain in the ass when you have the alternative of laying up the part with just resin, then doing the last layer with the surface curing agent (wax additive).

Bottom line:  if you already have some cheap resin laying around - use it up - but only use it for an application where you can finish the layup all in one go or where it's small enough that you won't mind sanding the whole damn thing between layup sessions.   

Now that we've discussed the differences between good stuff and crap, let's talk about the good stuff and the variations you can look for:

1. Polyester Resin:  Your bread and butter resins.  There aren't many things you could build where you absolutely shouldn't use a Poly resin of some variety.  There are different grades as shown by the link and the price difference accounts for differences in the final material properties.  Need more heat resistance?  Isophthalic resin is your friend. Just need something for general use?  I buy the Laminating Resin - Bond Coat B in 5 gallon buckets because it's the cheapest and it's strong enough for almost anything I need it for.  For example I'm going to build the molds for the MR2 out of this stuff but may end up laying up the actual finished parts with the Structural Layup Resin because it's more flexible and will have less chance of just shattering under a small impact.  But - it's also more expensive so building the molds and the parts out of it isn't financially sound since the properties it provides are actually undesireable in a mold.  You don't need or want your mold to flex. 

2. Epoxy Resin:  Much stronger than your average Poly resin, on average much thinner than your average Poly resin so it's better for flow coating.  The disadvantage is that it's far more brittle than the Poly stuff so I personally wouldn't use this for auto body parts.  I would use it for interior stuff or Carbon Fiber applications where flexability isn't desired.

3. Surface Curing Agent:  Because of the afforementioned lack of wax in the good stuff, you use this in your final pot of resin.  

4. Hardener: AKA MEKP Liquid Catalyst.  As far as I can tell these are all created equal so buy what's cheapest.

5. Talc:  This is like adding breadcrumbs to your meatloaf because relative to the beef the breadcrumbs are dirt cheap.  Talc bulks out resin so you use less to cover the same surface area. It also makes it thicker and reduces cracking.  I don't use this in the first layer or two but I do use it on the non-visible side of whatever I'm making. 

6. Cab-o-sil: Makes the resin more like a glue.  Good for joining panels that are made of fiberglass.

7. Gel Coat:  Regardless of if you're making a mold or a part from a mold this is the first layer you use.  It's basically the fiberglass equivalent of primer and provides a smooth surface on your finished part.  You need to spray it on to using a gel coat spray gun and those aren't cheap ($125 or more) but the good ones will save you tons of time you'd otherwise spend spreading the gel coat on with a paint brush.   There's two kinds of gel coat - regular and tooling.  Tooling is what you use if you're making a mold you're going to pull a lot of parts from.  Since I'll only be making parts for myself I just went with the regular stuff.

8. PVA:   I have no experience with this stuff yet but I've got a quart of it sitting on my supplies shelf.  It's used as a parting agent when making molded parts.  It's basically plastic dissolved in alcohol and it's only soluble in water so it will stand up to resin but you can spray water between your mold and molded part to remove it and help you pull the part off.  I've heard it's a nightmare to spray on correctly - we'll see.  The ease of parting benefit to me outweighs the risk. 

Category 2: Fiberglass Fabrics
The problem with fabrics is there are tons of different kinds so if you're starting out it's hard to know what you should be using.  I haven't tried them all so I'm only commenting on the ones I know.  All of the cloth's I've listed are part of a product category called E-Glass.  There's an S-Glass product set that's supposed to be stronger than E-Glass but I haven't used them yet. 

Cloth is stronger than mat but it's only stronger in two directions so when you're applying it you should do it diagonally and overlap the direction of the strands to achieve maximium strength. 

1. Chopped Strand Mat:  CSM is the meat and potato's fiberglass cloth.  You've seen it before at the hardware store.  It looks like a bunch of strands interwoven together loosely which is exactly what it is.  It tears easily by hand, gets fuzzy little strands everywhere, and generally makes a mess but it's cheap as chips, has equal strength in every direction, and is your most economical path to making just about anything out of fiberglass.  It comes in different weights.  I use .75 almost exclusively. 

2. Surfacing Veil Mat:  If CSM is meat and potato's this is apple pie.  When used immediately after the gel coat layer srfacing veil mat helps reduce the visibility of the pattern of cloth you use after it.  Think of it like a buffer layer before you start using cloth's with a looser fabric pattern.

3. Modified Twill Cloth:  This stuff is good if you're trying to make a part with a wierd shape.  Autobody panels are smooth enough that this isn't really necessary but molding parts with interesting angles is made eaiser with twill. It's far too pricey to exclusively use twill so you could use this as your first layer after surfacing veil mat to make sure you turn that corner well before you start on the CSM or Woven Roving. 

4. Woven Roving Cloth: This is the heavy duty stuff.  It's thick and is big enough that you can actually pull out individual strands of it by hand without completely ruining the fabric.  This stuff is good to use in corners of a mold because it's sturdy and you need stength in bends and turns. 

5. Core Mat:  I'm not sure how to describe this stuff except to say it's sort of like a foam pad in it's dry state, and an iron plate when wetted out.  You use this for parts when strength is a factor.  I wouldn't use it in a mold because it's too pricey but if you need to make a hood a layer of this between a couple layers of Veil and CSM will ensure a super high strength part. 

There's a ton more products in this category but the four above are your basics for beginners.

Category 3: Body Fillers
A lot of people just call this Bondo.  That's bad because unlike Kleenex or Q-Tips the product that gave the category a name isn't the best option out there.  Body fillers are what you use to fix a dent, fill a pinhole, or otherwise smooth out a surface with a small imperfection.  You shouldn't build up body filler to more than 1/4" or so or you're asking for trouble because the stuff shrinks over time and with heat.  Filling in that recess in your door with just body filler is a really, really bad idea.  People can become partial to a certain brand of body filler over time and that's certainly the case with me.  I love Evercoat products.  I won't use anything else unless it's for a throw away application where I don't care about everything being perfect.  I will never use Bondo brand filler again for anything but throw away stuff.

Within the category of body filler you have a couple of different types of products that are useful to the DIY guy:

1.   Kitty Hair.    This is body filler that has a paste like consistency and contains small strands of fiberglass which is where it gets it's name.  You utilize it for things where you're either filling large issues in a fiberglass piece or where strength is a factor.  This stuff is strong and reasonably light weight but it doesn't sand as well as other fillers and should therefore be used sparingly if posssible/practicle.

2. Light Weight Body Filler.  This is your meat and potato's body filler.  You use this for most jobs like filling slight imperfections or smoothing out a rough part.  It sands better than kitty hair but is stronger than skim coat.  If you're really in a pinch you can thin this with fiberglass resin and use it as a skim coat which will keep you from having to buy seperate products for different types of jobs like I do.  If cost is a factor for you it'll get the job done and is cheaper than buying a seperate product.

3. Skim coat.  Not as strong as Light Weight filler but it sands like it's not even there and is the best product you can use to fill in pinholes or other tiny imperfections before they come through during painting.   As indicated by the name, you should use this very, very sparingly and in non-structural type  applications.  Think of this as the product to help you feather out your repair into the adjacent area of the body panel.

The Hater Manifesto.

Despite youthful socioeconomic challenges I was determined to be an early adopter of computers and the internet. I wrote my first line of code at seven on a used RadioShack "computer".  I've been online for a long, long time.  That's afforded me some perspective regarding Online Persona's.  Generally I think there's room on the planet for everyone and as long as you're not hurting anybody (well...nonconsentually anyway) go on and do your thing.  There's one particular sub-culture that I really don't care for and I think the world would be better off without though: Haters. 

Haters suckle at the sour teat of failure with greedy mouths and jagged teeth.  They love it.  It gives their lives meaning to spew their bile and laugh at your missteps without having to go out on a limb themselves.  Take a risk, try something different, go away from the norm and there’s no shortage of people out there who would love nothing more than to spit on you and your efforts. 

Haters are like seagulls: there's more than the world needs, they squak constantly, they fly in and shit on everything, and you really wish you had a high capacity firearm every time a group of them spends too much time in your personal space.  There's so many in fact that people seem to have just become either immune or tolerant of them and their behavior.  I guess it's similar to capitalization, using there/they're/their correctly, or you know - actually reading. At some point you just have to stop caring or you'll waste all your energy on people who don't deserve it. 

If you rewind the clock back a bit to my dad's generation, it was a lot harder to be a Hater.  The reason is simple: no easy way existed to desceminate the Hate so you had to do it face to face.   It's a lot harder to tell someone in person you don't like something unless you can back it up with actual experience or expertise which your average Hater just doesn't have.  Today it's just too easy. 

It's been my personal experience that making things for cars attracts a ton of Haters.  They younger or less financially viable ones don't get why you would make something yourself when you can just get cheap parts off eBay.  The rich Haters don't get why you wouldn't just pay $800 to get a carbon fiber hood from Japan.  The smart Haters just want to spew all sorts of seemingly technical knowledge without actually giving you any advice on how that's remotely applicable to what you're doing. 

Given some of my upcoming projects I'm going to be blazing deep into territory where epic failure is an ever present reality.  If you're a Hater there will be plenty of cannon fodder.  I've got a limited amount of energy that I could either ply into my projects or spend dealing with answering the Haters.  I decided recently that I've spent too much energy already trying to explain things to people that may or may not have been Haters in the hopes that there might be an actual intelligent human being underneath that just didn't understand what I was trying to accomplish or why. 

I'm done with that. 

You're either going to take the time to write respectful questions in coherent and complete sentences based on the application of rational thought or as far as I'm concerned you didn't ask a question at all.   You're either going to tell me why you disagree with something and back it up with facts and citations or you don't exist.  If you can't do any of that then do the world a favor before you post a comment:  stop, take a deep breath, step away from the computer, and STFU.  I don’t care what you think.  I’m doing my thing whether you like it or not. I’m not doing this for you.

I do what I do and write about it because I know there are other people out there like me but they just don't know it yet.  Maybe they were too afraid to make a mistake or just didn't know how to get started but there's some real creativity buried just below the surface.  Maybe they'll discover a flair once they've picked up a paintbrush and wetted out some chop mat.  Maybe it's at the point when they grab a needle and thread and sew up some leather.  Regardless of what gets them going I want to help give them the courage to try.  I'm doing this for them and I'm doing it for me.  Everybody else can die in a fire. 

MR2-FA - Design: Applying the Styling Elements

Now that we've got a good idea of what the common and differentiated styling elements of the Lexus lineup are, let's take a look at the base MR2 and how each one might be applied. For the purposes of this exercise and to keep it easy to visualize I've re-organized the list by features of the front, side, and rear of the vehicle. You'll notice in each section that I've made at least one concession to practicality. What I'm going to be doing will be hard enough without my being completely unrealistic about what parts I wouldn't enjoy making.



Vehicle Front

The Front Bumper should have the following styling elements:
- An integrated front lip with canard shaped ends to funnel air around the wheel
- A radiator intake that slopes outwards from the top down
- Pronounced Side air intake vents for the brakes
- Non-Pop-up headlights

Consistent with the Guiding Principals, it should also:
- Have proper ducting to the actual brakes
- Use a properly shaped air intake funnel/outlet for the radiator (Opening smaller than the radiator, opening up to the radiator, then narrowing down again to speed up the air as it exits)
- Seal the bottom area of the car so that air doesn't escape in unintended ways

Commentary:
This is all pretty easy to do since I have to make a new front bumper from scratch. Right now I think I'm going to create a frame out of wood then sculpt the thing out of urethane foam. In order to do this right I'm going to have to relocate the radiator and create the ducting first, then build out the bumper shape. It's sort of an inside out approach but it's the only way I can really be sure that the venting will work with the future shape. Doing it in two parts also ensures that if I do something wrong on the ducting I can rework that portion of it without having to completely redo the entire front end.

Front Fenders and Hood should have the following styling elements:
- Flat hood with venting as appropriate to the application
- A ridge that moves forward from the A-Pillar and is integrated with the front body work.
- Front fenders that move towards and either slightly enclose or totally enclose the headlights
- The Hood should become narrower as it moves towards the front of the vehicle
- The fenders should be flat on the sides.

Commentary:
Here's where applying the styling starts to get tricky. The MR2 hood clearly isn't flat and it also doesn't narrow towards the front unless you count the cutout for the headlights. That's a problem because it means that all the mounting points for the inside of the fender are in a straight line down that gap.  This will create problems because if you make a fender that comes inwards and overlaps with the headlight you've got to have enough vertical space to get the bolts in there or you're going the ghetto fabulous route and using zip ties which I've already said I won't do.

About the only solution I can come up with is to raise the level of the fenders slightly. By raising the overall height of the fenders I'll give myself enough room to get to the bolts and bring the fender in towards the headlights. It will also allow me to introduce the ridge present on the other vehicles with minimal risk. This shouldn't be a problem so long as the inside lower portion of the fender actually matches the OEM ridge and mounting points. This is going to require a multi-part mold: one for the outside portion of the fender; one for the inside portion and the mounting tabs. How much I raise the fender and how far forward it comes is completely dependent on how I mount the headlights so I'm going to have to pull the hood, pop-ups, front bumper and mount the headlights before I can even start on the fenders.

The fenders will also need to be flat on the sides towards the bottom. The MR2 versions are rounded but that's easily solved with foam. Since I'm molding a completely new fender I can flatten the rounded area with foam and body filler then pull the mold from that.

Once the fenders are done it should be relatively easy to figure out what the hood should look like I'll have to keep the width at the back in order to maintain the OEM mounting points but I'm confident I'll be able to figure out how to make that work. I'm also probably going to vent the radiator over the hood. I've seen numerous examples of people doing this on MR2's.  It's just a matter of figuring out how I want to do it in the context of all the other work I'm doing.

Concession to Practicality: Headlights.
For headlights I bought a set of OEM Celica headlights from the last version of that car. I've seen someone else do this and it looks close enough to what I want that I'm going to run with it. If I had a choice would I use something smaller? Absolutely. The problem is that I've made headlights before and it's always more of a pain in the ass than it's worth. They leak and you can't find the hole. You have to re-do them because the lights aren't aimed correctly.  You need to cut acrylic plastic to fit and then figure out how to deal with the angles.  The list of what can go wrong on custom headlights is pretty long. I'll settle for painting the insides of the headlights to match the car. That'll at least give the appearance that they're smaller than they are.

Vehicle Sides
I'll be upfront and say that the sides of the car are going to be the biggest problem for this project. Almost every element of the sides is going to require a ton of effort and planning so rather than just a list I'm going to take these one at a time.

Hard line below the window that runs the length of the car
I don't know how I'm going to do this. Or, I should say I don't know how I'm going to do this and do it right. The easy way would be to make a couple of strips of fiberglass that blend the difference between the flat side of the door and the top, rivet them on, and then fill the area with body filler and smooth it out. I don't want to do that because it will invariably crack and look like complete crap. This means that I have to do it with metal. How? No idea. I'm going to noodle on it for a few weeks and ask for some advice before I do anything. It's going to be tough regardless though, because any line that long has a high probability for one of the parts being slightly off since you have to go across three separate body panels for it to work. If anything is even off by one or two millimeters then irrespective of any other work I do the whole car looks like shit.

Door Mounted Mirrors:
This one is my concession to practicality. There's a nice solid mounting location for mirrors on the top of the door behind the A-pillar and if I used another location I'd have to cut this out or fill it somehow. I will make my own mirrors though.

Side Side skirts parallel to the ground and the front bumper
This one is the only easy one on the side. I just need to create the shape out of foam and glass a mold. I won't start on this till the front bumper is done to ensure that everything lines up.

Side moldings
This isn't too bad but it's a lot of work. All you really need to get rid of those hideous plastic moldings on the door and rear panels is some plate steel, a welder, an angle grinder, some good body filler, and Mad Skillz Yo. I have all that on hand.

Side Rear Intakes
Obviously the MR2 has these. The OEM piece is even fiberglass so I could concievably just use it as the base for the new ones. I won't, but it's still not that hard. More foam, some flat plywood, and body filler will do the trick here then I just need to pull a mold.

Flat doors
Aaaand this one is the killer. If you stare at the MR2 doors for a minute or two a couple of things should jump out at you that make this a problem.

1) The half circle curve at the lower edge of the door starts at the very edge of the slot that leads to the air intake.  this is a problem because I need to figure out how to flatten out not one but two seperate circles that are interconnected. 

2) If you picture how the window rolls down, you can imagine that there are supports on the back side of that section for the window and for side impact crash protection.

3) Cutting any of this stuff out, without knowing what's on the other side, is a recipie for killing yourself.

I can think of a couple of ways to fix this but I won't know what will work till I disassemble the doors some more, drill a few holes, and test it. What I'm thinking now is that I could use the OEM air channel as a guide and cut it down the center horizontally. If I cut vertially at the forward most point of that recess, then weld in a flat piece of metal, I should end up with a look very similar to the rear of the doors on the LFA.  It'll have a slightly stronger angle inwards at the top but we can write that off as a model specific design element. 

Is this safe? No idea yet. The last resort will be to build out some fiberglass add-ons like what I described above for the body line and riviting them to the body. Again, I don't want to do this because it will invariably crack and I'm going for durability. I'd rather work with some of my fabricator friends on internal reinforcements for the door sheet metal. 

Vehicle Rear

Now that we're at the back of the car it's time for a different picture. As with the sides of the vehicle let's tackle these one at a time.



High mounted license plate
Looking at the MR2 this should at least theoretically be possible. Clearly there's a pretty big area in the middle-rear of the car that currently houses a center plate that doesn't do anything except look pretty. That center plate conveniently meets up with the trunk lid. We'll see what I find when I remove the piece but it should be possible to combine the two into a single piece.  I'll need to be smart about how I construct the area around the tail lights and for the rear keyhole. Unlike a car that has the keyhole and latch integrated into the trunk lid, the MR2 has the the keyhole in the body.  This means that the U hook that plugs into the securing latch is actually on the trunk lid and not the other way around like on all my other cars. 

Fastback Engine Lid
This one is going to be interesting. Things like this have been done before on MR2's but I haven't liked the design of any of the versions I've seen. Here's a couple of examples: 





A lot of people like this look. I don't for a couple of reasons:

1) Even with the integrated openings it has to interfere with your rearward visibility which is never a good idea in a road car.  

2) The lower version looks like the inverse of something you'd put on a Mustang circa 1985.

3) The transition from body, to rear window surround, to engine lid when done this way looks busy and amaturish to me - like they just couldn't be bothered to remove the rear window surround and see what was underneath...so they just slapped something over the top of it. Which, honestly, is probably what they did.

Ok, so I don't like that style. What do I like? Go find yourself a picture of the Lotus Evora with the trunk lid open.  No, I'm not going to post one - go use Google Images. 

There's two windows in the back - one that's an integrated part of the rear of the interior and one that's on the engine lid. The MR2 obviously has the interior window covered so i just need to make a one piece engine lid with yet another window. The problem isn't that part of it - the problem is the hinge mechanism. Since the Evora was designed on a clean sheet of paper they could do whatever they wanted to get the hatch to swing up. On the MR2 I'm constrained by whatever mounting options will fit on the surface area I find underneath the rear window surround when I pop it off.   I have no idea what's there yet. 

Worst case scenario is that I can't do hinges and end up securing the lid with a couple of Aeroware latches on at least two corners .  This isn't the worst thing in the world since Aeroware latches are a massive asthetic improvement on hood pins and are much stronger to boot.  

Rear bumper shape
Per the analysis this needs to run parallel to the side skirt at least to start, then curve upwards as required.  I'm obviously going to have to make a rear bumper, if for no other reason than if I succeed on moving the license plate area up I'll look like a ricer Civic with two license plate mounting locations.  Don't laugh - I've actually seen cars like that.  Ok, now you can laugh.  Since I have to make my own I can make it any shape and height I want.

Rear diffuser
This one is going to be tricky because of where the exhaust sits on the MR2. Personally I'd love to have a dual center exit exhaust, but that's not a decision I'm prepared to make until I've got the V6 dropped in. I'm going to have to leave the diffuser part of the bumper for the engine project and just call it good with making the upper part of the bumper.

Downward sloping tail lights
With all the cars I've worked on over the years I've accumulated a lot of crap.  I recently threw out a lot of it but I almost always keep lighting related stuff because you just never know when it'll come in handy.  At this point I've accumulated five tail lights, four headlights, at least 100 light bulbs of various sizes and types, LED banks, brake lights, reflectors, wiring harnesses, loom, and housings.  If I can't make a set of tail lights out of all that I should quit right now.  

Flat trunk lid accentuated by a small lip style rear wing.
The MR2 trunk lid has a quarter circle shape curve to it.  As with the bumper I was going to have to make a new trunk lid anyway so I can make it whatever shape I want. This introduces a problem though because whatever angle and shape I make the trunk I have to carry that same shape into the rear fender.  Since the rear fender is metal that means more fabrication work unless I can come up with a clever way to blend the two looks.

Concession to Practicality: Rear Window
I salvaged the sunroof from the Lexus because I thought it looked about the right size and shape for a rear window on a MR2 fastback.  I measured it out and I was right - it's damn near perfect.  It's not light though, and a lighter solution would be to use Lexan or some other type of plastic but the problem with that stuff is it isn't nearly as durable as good old glass.  This will make the lid heavier than I want it to be and adding weight up high is the worst possible place to do it, but I'd rather do that then have my plastic rear window melt as I'm driving down the highway. 

That's a lot of problems to overcome.  Would you keep going?  It doesn't matter if you would.  I am.