i've experimented with making a custom paint where i use a base coat of pure aluminum flake (the metallic bits they use in all metallic paints) and no colour but with a laquer mixed to it 50/50, and then a top coat of pure laquer. the finish is really amazing, it looks like a rough metal finish but its smooth and shiny to touch. its looks like real metal, its hard to describe but i've got a pic of a rocker cover i did somewhere, i'll post it if i can find it. i've always wanted to do a full car in metal flake with no colour, but i doubt i'll ever get the chance so feel free to be the first one on earth with my idea. it would look good for wheels too, i've used it on engine bay parts and interior bits and it looked ace.