If you're looking for the black cardboardy stuff that's pretty water resistent, try Restoration Specialties in PA. http://www.restorationspecialties.com/ If you're looking for ABS panel or or Masonite, I'd look in your Yellow Pages.What exactly are you looking for?
Luan wood is great to use. Available in nearly any town in the USA. I heard about it from Sid Shavers years ago.
I used the ABS panels from ROD DOORS but they have gone out of buisness sad to say. Try a plastic supplier or sign shop , they should have ABS. That stuff works great on interior panels ,real easy to heat and bend, glue patch , what ever. I believe there was just a thread on this very subject about a week ago. MIke.
Wow, I hadn't realized that Rod Doors was gone, but sure enough, their website has only a thank-you. I always thought they were more streetrod than hotrod but still hate to se another car product vendor gone.
ABS sheets are available at Home Depot along with 1/8" veneer panels I just checked them out today at lunch, I'm going with the veneer but will spray some Thompson water sealer on both sides before covering the panels with vinyl...
I guess that ROD DOORS probably did cater to the street rod crowd. BUT I did my own interior and needed something easy to work with so I went with their product, my kids were little and I didnt want to spend huge cash on an interior that I would worry about every time I took em somewheres. Now that they are much older, I will someday yank all the bland interior out and install the interiot that I have wanted all along. Mike