[minibajaman]

For the Baja SAE cars I worked on we used 1/16" thick Lexan and painted the inside. It looks great when new, but scratches easily so is really only good for one season. It also would eventually crack around mounting holes on older non-competition cars. But for a race car it works good.

For my personal buggy I decided to use 1/8" HDPE. It is really cheap compared to Lexan, but only comes in black or white, and is not really paintable. It is more flexible than Lexan and less prone to cracking, but does expand more in the sun. It has worked well for me so far, but does not look as nice as fresh painted Lexan.