The main thing you wanna be sure and do when painting them is getting them prepped properly which would include a good cleaning, scuffing the surface with a very fine paper or brilo (sp?) pad. Your first coat (because it's plastic) should be Adhesion Promoter which you can get at any auto parts store. The stuff I use is made by Duplicolor. Then start applying your primer, paint and clear coat. If it's me, I apply a couple light coats of each and maybe as many as 3 coats of the color and clear but be sure they are not heavy coats. There are paints out there that are geared towards plastics but you can use any kind of automotive paint when prepped properly.

 

i used krylon, fusion spray paint. it's for plastic.