We recently put Fade Away to the test on the hard plastic door panel from a '70 Camaro, and came away very impressed. The door panel had been spray painted black in the past (it was originally molded in brown), and the cracked and peeling finish looked sloppy at best. After stripping off the old paint with lacquer thinner, we thoroughly cleaned and prepped the panel (using the surface prep solution supplied with the kit) before spraying on the black dye.
The dye was easy to apply-basically like spray paint-and the finished panel came out looking fantastic, with plenty of gloss and a true black color. In fact, we're planning on re-coloring the other door panel, the back seat, and much of the rest of this Camaro's interior so the whole cabin will have a like-new look.