Making fiberglass door panels is a rather easy process that you can do by yourself guided by a set of simple instructions and with the correct tools and materials. Fiberglass door panels part 2 of our custom door panel articles door panel prep if you are following our procedure for making fiberglass door panels for your interior you have purchased your supplies found a workspace removed and disassembled your door panels and thoroughly cleaned them. Fiberglass door panels are very suitable for your car as they are durable and very strong.