MM54 and Long_Voyager were right and have been awarded one “I told you so” point.
There were two areas where the original paint on my wife’s FJ spare tire cover had been rubbed off (I’m assuming there was a canvas cover with an Eagle or American Flag or Peace Sign or something). I wanted a matte-black finish that would match the roof rack, and thought I’d use Plastidip. To summarize, on the areas where the paint was intact and looked fine, the Plastidip applied smoothly and evenly, and those areas continued to look good. The areas where the paint was gone refused to hold the new goop, and looked even worse. I prepped with very fine sanding then dish soap and water, but maybe should have used a degreaser. Whatever, it looked like crap. Enter the advice of fellow Oppos to use trim paint:
The sangria was my idea, but did seem to help. In the rough areas where the Plastidip was uneven and thin, it was difficult to remove but came off beautifully with the SEM plastic prep solvent. 4 coats of SEM Black Trim later, I’ve dared victory!