Many cars have plastic trim that comes from the factory black. On black or dark-colored cars it isn’t a problem, but if your car is silver or white, the black really stands out. The plastic material can be painted to either match the color of the car or painted a different color to stand out more. With some paint and materials found at an auto parts store, your plastic trim can be painted in only a few hours.
Sand the plastic trim pieces using 400-grit sandpaper. This slightly roughs up the surface and removes any blemishes or nicks in the plastic. Once the plastic is completely sanded, it should look dull with no shiny areas. Sand over it again using 800-grit sandpaper to smooth the surface. Rinse the trim pieces with water, and allow them to dry completely.
Place masking tape and paper around the trim pieces to keep paint overspray from getting on the surrounding surface of the car. Spray a thin coat of adhesion promoter on the plastic, and allow it to dry for 30 minutes. This helps the new paint adhere to the plastic and prevent future flaking and peeling.
Spray three to four thin coats of paint on the trim pieces. Keep the coats thin so that there are no runs in the paint. Wait 10 minutes between each coat and 4 hours before handling the trim.