We are replacing some broken plastic pieces in the 182 and are talking about repainting all of it, as the older stuff is badly discolored but otherwise not cracked or brittle. From what I understand, the FAA is fairly lax about interior upgrades as long as there are no structural changes (and you have a burn cert for fabrics). I tried googling and didn't find much in the way of resources specifically dealing with interior painting (plenty dealing with exterior). Can you just spray the plastics and seal them with whatever you want, or are there required types of paint to be used? I'm sure homebuilders would have the most personal experience with this stuff, so please chime in.