I would think talking to a company like Sikkens or Dow Corning would be a good start.A bit of a long shot here but here we go:
I'm in the process of designing a few accent pieces for the fog light covers and the diffuser. I'm going to make these out of aluminum but will paint them charcoal gray, just enough to hint that there's something going on in there.
Now, my father has access to an industrial-type oven which he uses to work with metals. He suggested the possibility of perhaps baking the paint to improve the finish and durability.
The thing is, we have no idea about the process. Does it depend on the paint? How long and at what temperature should they be baked? Is it even literal baking or is it a different process?
I'm flying blind at this point so any point in the right direction would be good.
Interesting project. Good luck.