When themes go bad

^^^

Yep, i'd say that about covers it.

according to how heavy you would do better avoiding the self tapping and drill holes and follow the guidelines for your safety equipment for bolt and washer specs.  Its probably best to go overboard on how well you attach the stuff than have it fall apart on the track infront of someone.

By that standard, Brian (btp76) should have 20 million flat tires.  'Cause seriously, his car is about 75% self tapping screws.

However, using real bolts with washers isn't a bad idea.

Someone on here has a star trek enterprise on their miata? i think.  It looks like it hangs off the back 3-4 feet.

Dont use drywall screws.  They snap pretty easily.  Deck screws are much stronger but dont have much surface area to hold the head from popping through the sheet metal.   Fender washers on the sheet metal and plywood side with bolts and locknuts would probably be the best way to do it.

Make sure your brake lights are visable behind whatever you are doing or mount an extra set on the way back of your addition.

Were you thinking this?

we actually created a sandwich of 2 foam types, then braced it with metal strapping, and bolted it to the hood/trunk through it's back bracing. it works VERY well. Aside from the crazy crosswinds at Gingerman, and our first race on the theme @ CMP (we needed to improve the bracing on the tail of the dragon) it's done the last 3 races with almost no mods at all. the nice thing, since it's bolted in, we can take the head and tail off and put it in the trailer for transport to help protect against damage. the best part, is it has no mass, so WHEN it brakes off (not if) then it's not going to cause a catastrophic accident. To quote RobL when our tail broke:

"Hey it's snowing! Ptooey-Phtpph why does this snow taste like paint & styrafoam??"

only Rob would know what paint and styrofoam taste like.

I just wanted to say, I like where this thread is going.

We stuck out the back by about 2ft, and were angled upward a good bit.

The first thing to get hit would have been our bumper, but Jay made us weaken the rearward supports with some upward cuts to ensure the whole mess would collapse out of the way and not become an impalement device.  Honestly, it was a good call.  The odds of another car getting tangled up with our butt is remote, but this is Lemons.

Make sure your stuff is well attached and doesn't present a danger to others on the track.  I'd use the "would I want to hit us from behind in a early 70's Honda?" rule of thumb.