PVC foamboard (expanded PVC) can be heated and bent at lower temperatures than ABS, and it's also way less expensive than ABS. A 4' by 8' sheet of 6MM pvc foamboard is about $60 from a sheet plastic supplier. You can cut it with standard woodworking tools, and it can be stapled to. It's also lighter weight. I would think 1/4" (6MM) thick would be plenty.
Here's some 3MM PVC foamboard formed with heat and used as a headliner. CLICK HERE
No one lives forever, the trick is creating something that will.
Last edited by DanTwoLakes; 04-11-2012 at 11:14 AM.