me n my brother painted the lower lip on my old ra60, I dont think we sanded it but i know we cleaned it be4 the primer. In the end it started to flake, started as little chips from rocks.
Im thinking of spraying the black part on the bumper on my ae92. those of u with ae92, u know how the bumper is already rough..... u reckon you'd have to sand that? Cause it has like a texture alredy, if you sand it, it'd go smooth.