I have the Q-tec spray, matches great. I used it on plastic and the only thing I've noticed is you do loose the metal flake if you don't clear coat over it. It seems the flake on the surface where you see it just falls off after awhile. The silver still looks great though, and from 10 feet away you wouldn't notice.
2013 JKU Sport, billet, auto, 3.73, LSD, 315/75/16 Duratracs on MB 72, 10A springs, Bushwacker flatties
Sold - 2005 TJ, red, auto, 3.73, 33" Duratracs, 4" lift
Ice storm casualty in 2007 - 2003 TJ, green, auto, 3.73, 33" Duratracs, 4" lift