Painting Black Plastics on a Precedent

[Cherig]

I just bought an old precedent from a neighbor and want to fix it up. I feel the black plastics all the way around are in good shape but are a little dull. I am going to get a new body so I don't need to paint that. My question is how should I prep it? How and what to clean it with? Do I need to sand? I feel it already has a rough texture so I don't need to sand. Do I use a flat black paint? Any advice will be greatly appreciated!