Originally Posted by ants_oz

Guys don't waste your time with plasti-dip. The first time you turn your heel on the running board, the coating will rip and lift.

Your only real option for any kind of lasting surface is powdercoat, but that would require the running boards be removed, the aluminium face separated from the plastic, and all the rubber nabs removed. Powdercoating is about as robust an applied coating as you are going to get.

Liquid paints are just too soft - the tiniest pebble or grains of sand embedded in the bottom of your shoe will scratch and mar the finish.