Cleaning vinyl bed side panels

[grillzy]

Wondering what a good product is to clean the vinyl side bed panels etc. Years of build up of dirt. Also anyone re used the covers and re attached to a new backer? If so what did you use for a backer? Not sure what the cardboard stuff is called but was thinking blatic birtch ply would be a stiffer option.
Grillzy

[pound41]

problem you will have with birch plywood or anything less bendable than cardboard is the slight curve at the front where the bracket ends and the panel screws to the side of the bed. I have good panels but want to add speakers so I am making birch panels that I am staining. I guess you could score the back of the plywood like I have seen done with drywall and plywood in building archways
but they weren't going to be removed like your panels will. I hope others smarter than I might jump in and tell us how do do it
Good Luck