hi! i have a black painted, machined lip finish aftermaket wheel..couple weeks ago i hit a cruff.....its all mess up on the side wall of the wheel...i wonder can i sand it like sanding on an aluimium wheel? can i even fix it that way? it won't be as shinly as before though right? how do i make them all shinly again? cause they look very dull and old now! thanks you!