[Otter74]

I Plastidipped my wheels satin charcoal because they were so shiny, and I hate shiny. Now they look terrific. If you think you might ever want to take the Plastidip off the spoiler, I think it’s going to be a challenge, more so than on a hard surface. But, as John S says above, you give yourself the best results and best odds of relatively painless removal if you do numerous thin coats. I doubt you’ll need to do more than touch it up occasionally, though.