66 Miata Batmobile Build

Hey, thanks a bunch guys!

I went down to 225/50r15 tires in the front - a little wider but also a little lower profile. So now the front is nice and low again and also the tires don't scrape the inside fender well when turning hard.

I had to do two rounds of recutting on the outer fender lips (and that's a lot cutting of grinding!) but I finally have it to where I don't get any rubbing anywhere during normal driving, even when I hit a bump on a corner. At least not yet.
Of course, with a passenger and more weight and a full tank of gas, I might end up needing to cut more. But for now it's good.

The rears are cut with 4" of vertical clearance between the top of the tire and the fender lip.
The fronts have 3" of vertical clearance.

So now the two layers of sheet metal that come together at the rear fender lip are completely separated, and I noticed the driver side door was sticking a little more than before (it's always stuck from bad bodywork and a wreck that a previous owner had.) So the body might have a bit more flex as a result of all the chopping.

Trunk SIdes and Tail Lights

I just finished the trunk sides and tail-lights!

First I made the patterns in cardboard, then coroplast. I used the coroplast pieces as patterns to fabricate .023 aluminum versions. (I had to buy the bigger Harbor Freight bending brake for this.)

I made the mounting blocks out of a 2x8, and had to carve the body contour into the outer blocks with a dremel until they fit.
The wood is pretty heavy but also very strong and forgiving.

The taillights are cheap $8 units, and I had to go to three different auto parts stores to collect all six.

The wiring seemed to take forever, but now I have six working taillights, four working brakelights and turn signals to boot. (Not counting the fin.)

The paint is currently Rustoleum flat black. I rolled on a fresh coat over the whole car last week. I also rolled a coat on to the faded vinyl top, and it stayed sticky for a day but now it's fully cured and even dried glossy. Looks a lot better! Don't know about durability but the top is pretty trashed anyways so I thought an experiment was in order.


I've been framing up the rear fenders. I tried to make them big and muscly without hiding too much of the rear tires.

Here are pictures of the frames as I have them right now and also with them fleshed out real fast in Photoshop:



You NEED to weld the fender gap back together. That is a structural section of the car and must be held together. Leaving it open will cause excess flex during driving and will most likely result in the eventual destruction of the kit you're putting on top, or possibly even the collapse of the suspension over time. There are several several tutorials on youtube that show the process for when a widebody kit is put on racecars and such. (I'd link them but I'm at work and youtube is blocked)

Here's a build thread on a WRX that shows the process too. The fender cutting starts about halfway down the page. Wide Arch, 400+ Newage rebuild for the road - Page 4 - NASIOC
Thanks for the heads up. I'll check it out.

Seems like I still need to trim an extra 1/2" off the right side and 1/4" off the left. On hard hard cornering I'm still getting a little rubbing on the passenger side.

So I have the first 14 aluminum plates done on the new rear fenders.
It takes about 2 hours per plate which includes pattern making, cutting, bending, fitting, starting over when a plate doesn't fit right and of course riveting.

I really like the riveted look. And the results are light and permanent.

Next I'm going to mount these to the body and then I'll need to reframe the bottom halves to match. (The modules got a bit of a curve in the lateral dimension.)


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Rear fender bottom halves, trim plates.


I reworked the frames for the bottom half of the rear quarter panels so that they come down 2" lower at the tire.
Also, I reshaped them to match the banana curve of the top half.

I completed all the plates for the bottom halves (about 16 hours work). I staggered the seams for visual variety and tried to match the curve of the top half as I riveted each plate into place.
Alas, at the end of the day the bottom half doesn't quite match up with the top half. The skin is made up of 'stressed' plates, which makes for a structurally strong form, but the stress of the plates gives things a curve over any distance (A jig would force things straight, but I haven't made a jig.) In any case there's about a 1/2" gap at the front and rear.

But that's okay because I plan to use a trim strip to:

1. Attach the two halves together permanently with rivets to make a rock solid super stiff form.
2. Hide the uneven seam / gaps between them.

This is as close as the two halves will get with the squeezing pressure of the tape:

Trim strip pieces all made. First two riveted:

These parts look small in the photos but each fender is about 4 foot 6" long!
Wow this is incredible I have just read the entire thread from start to finish and I have to say I am speechless! Thank you for sharing this with everyone!

Finished the trim strips on both sides.


I'm considering mounting these to the car as-is and then building the other pieces of the rear fenders to fit.

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Spent 8 hours today making mounting brackets and mounting point reinforcements, installing everything and working on the fit.


When it's a bit warmer I'll mount and paint them.

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Hey creebobby, great job. It's interesting how this project has evolved as far as the materials and approach you've ended up taking. Good for you for never giving up. :thumbsup
Rear Fenders Mounted!

Fenders are go!


It was a big task to get them on, but now they're mounted and rock solid.
I still plan to add an extra section at the lower front and a trim plate on the the inside rear tips. I'd also like to add a trim strip made of one curved piece of 1" wide aluminum along the top edge to smooth out the profile and hide the shingled stair-stepping. But in any case it works and is impressive as-is.

I came up with this simple bent sheet-metal stabilization bracket. Just this one piece did wonders to lock the part in place and stop any shaking.
Simple mounting brackets in the wheel well. All in all each fender has 15 points of attachment.
Brackets along the top inside edge and cut-out for accessible refueling:

I saw these fenders as being 'experimental', in that I wanted to:
1. Learn if this method would work at all.
2. Find out how acceptable looking the results would be if I went with a simple shingled overlapped-plate build method.
3. See if I could get them on my car in a budgeted amount of time. (2 months.)

Based on those parameters I'd say they're a success.
I'm nine hours in on building a big Bat-head for the front.
I've kept it geometric so it shouldn't take too long I hope.

I marked the lines and pulled contours:
Traced the contours:

I used the contours to work up patterns freehand, then used those patterns to make other patterns.

Patterns, coroplast parts and critical elements cut out of 1/2" pressure treated plywood:


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Bat Head Framing

Well, here's the frame for the Bat-Head as it exists right now:

Here's a Photoshop Mockup of a front end drawn over that photo:


Any thoughts about this design?
Thanks Tripleasg - I definitely plan to keep going!

I shortened the chin in by 1.5" and took out the 'crook', though I might still cut one into the new front edge. I haven't decided yet.
I also widened the top by about 3.5" and shortened the rear edge height by 1/2".
Now it looks more like what I had in mind.


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Thanks for the encouragement!

I refined the head box a lot more - it was a little wide on the car so I brought it back in halfway. I also shortened the nose by another 3.5".

I also made and installed mounting brackets:



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