I've had my HP design wheels for about 6 months. They are shadow chrome centres with a machined lip around the edge. After washing it the other day i noticed a lot of small black spots stuck to the outer part of the rim. I thought it was brake dust but when i tried to scratch it off with my finger nail it didn't budge. I was thinking that the brake dust had baked on or something and rooted the clear coat thats over the machined pat of the rim.

Has anyone else come across this or know what it is?

Here are the wheels

IIRC, thats the brake dust/road grime that has "eaten" into the wheels finish. Its very important that all alloys are cleaned weekly. The wheels should have a few years warranty on the finish, see if they will repair them for you. (I am looking at ANZ wheels, they have 3yrs on finish and lifetime on construction)

Hope that helps