what coaches have plastic/fiberglass storage bins?

After reading your first post on the other thread, I'm not understanding what you're asking for. Are you meaning the bay's themselves? If so ( I might be wrong) the supporting frame work is steel ( that supports the bay's). Even if the bay is plastic. Ours is lined with a plastic of some sort, but what's supporting it is steel.

I don't understand why they make the walls and roof out of aluminum, then put the lower section with the storage bays together with steel and the lousy paint job. :M