i used a paint designed especially for plastic on some parts on my toyota. it was called Krylon Fusion. It supposed to never chip, peel or flake w/ zero prep work. I prepped anyway and the stuff has been holding up for the past 3 years.

87 22R PU, 2 body lift, 33 BFG muds, 4.88's, F&R Lock-Rights, Rancho Shocks, EB's Street RV Head w/ 268 Cam, LCE Header, 2" to 2 1/4" exhaust, Flowmaster 50 series, Magnaflow high flow cat, complete Herculined SR5 interior, V6 BB, MC, and calipers.