This was my initial thought as well. Find someone who has a wrecked trailer and there you go.
As for me in Florida, all i had to do was pay sales tax when I bought it and I'm done.
Acetone or Xylene. Hot stuff and use only outdoors for the adhesive.
Both sides may or may not be painted. I am of the belief that a trailer manufacturer will only buy one-sided painted metal. Quite often the other side is white. All you can do is check out a small corner somewhere. We are...
We work with polycarbonate a lot. I totally agree with rlitman that you need oversized holes when you drill polycarbonate. And do not tighten screws too much as it will cause stress cracks and ultimate failure.