Powder Coating

You could scuff the powder and clear over it, proper 2k (as in isocyanate hardener etc) would give it a shine and be pretty durable. Probably won't last too long with stone chips and suchlike though.
I think there's powder that's just laid straight on, and there's a 2-stage one with primer/epoxy powder on a blasted surface, followed by colour powder. But I'm not 100% sure on this, a coater would be worth asking.

Thanks for your time gents, i'll check with the coaters but its one of those jobs you don't how good till its done, supose trust is the word.

I had the intake manifold coated in black gloss by the guy who did the engine frames for our aircraft.

I spent a bit of time with him and it turned out they were working with a coatings company and had secured a deal with one of the north sea oil rig builders. I had him use that on it as it had a spec above and beyond what the engine could create, save catching on fire.

The coating he put on went on hot and now looks like shiny neoprene or the kind of finish you get on uh, intimate rubber adult novelties.
Shiny but not a deep shine, the surface is doing the reflecting. I think they had a few colours, mostly bright primary (red, yellow).

He said that it was hard to add a matting agent as it messed with the compound and made the surface finish less durable. A little bit of a buff with some car wax and this was shiny and stayed shiny. Not sure if the bits you have are coated already but what you decide to get put on in the first place makes a big difference.

You'll have to ask Stefan how it's doing, but so far it's been covered in petrol, grease and been heated and cooled and last time I checked it still looked as good as new, albeit dusty.

I'd have to dig their name out of the phone book if you want to give them a call. They're a bit of a ways away from you outside Bristol but the work they did for us was fantastic and not too expensive. He has an oven and booth you'd be able to coat a Mini in...

Edit for picture of offending item



--Phil

this man is correct. for 99% of car parts, paint is a much better finish than powder coat- especially stuff like wheels and suspension components. aluminium is particularly prone to water getting into chips and lifting the whole surface off, leaving white corrosion underneath, id never get anything made of aluminium powercoated.