For race cars I spray paint.
For road cars, up until now, I kept the chrome plating as provided in the kit. However, with the one that I'm working on now, the plating came off in some spots (Fujimi), so I put the wheels in oven cleaner and after 2 minutes the chrome platng was gone

all that was left was just regular plastic. After thourough cleaning, I'll spray them black enamel and finish with Alclad II Chrome. Expect to see pictures in the next couple of weeks.