@Tal did you ever figure something out on this? I screwed up royally - strapped a dry bag with a drill and other tools to the passenger seat and it slid off and banged around on my rim. Did a good amount of damage, including destroying my tire pressure monitor, but I guess it could have been worse.
Wondering if there's a special kind of paint that should be used, or just regular automotive touch up paint? It'll never be perfect, but it bugs the snot out of me to see it as a constant reminder of that dumb a$$ mistake.