Update: So I sprayed all of the plastic pieces on my 4Runner...front bumper plastic, grill, mudflaps, complete running boards, license plate holder, etc and I have been wanting to run it through a car wash to see how it held up...you know one of those drive through car washes that scrape your entire car, while blasting it with a high power jet of water and then a wind tunnel with winds of tornado speed.
Glad to say that the plasti-dip held up well...no scratching, no peeling, etc The only place that I can see a problem is where one of my dogs jumped in the back and stepped on the bumper and one of their claws cut the plastic dip...other than that it cleaned up, held up and looks good