Industrial Velcro works great if you have a nice flat piece of steel with a really good quality paint job on it to stick the Velcro to. If that's not your case, Vince is totally right, it doesn't work for attaching door panels or any other kind of panels.
Don't use ABS, it doesn't bend, and waterproof panel board would be my second choice. PVC foamboard is what to use for the panels. If you want to take the panels off, wood is not what to attach the panels to.
No one lives forever, the trick is creating something that will.