I love the white 16″ wheels on GBMINI, but they do get dirty. I washed the car before MINIsOnTop but only today got to wash again after more than 1000 miles! I have tried various things to keep the wheels clean – last September I had Green Stuff brake pads installed; they are supposed to reduce brake dust but I don’t recommend them.
My latest discovery is Insulator Wax from AutoFanatics (local to me) – actually I like this wax so much I have used it on the bodywork too, to great effect!
Anyway, the Insulator Wax is supposed to help keep the wheels clean. So this morning I started with wheels as dirty as you see, sprayed them with P21S then pressure washed the car, then the wheels. At that point the wheels were basically clean.
Next I washed the car with Zymol shampoo, and wiped the wheels using a sponge soaked in the same shampoo. Then I hosed down the car, dried it, and dried the wheels with Bounty towels.
So here’s before and after:
I am pretty happy with that!
The P21S does a very good job of persuading the dirt to lift off the wheels, but the insulator wax has further improved things so that I basically do not need to rub the wheels – they come clean with the pressure wash alone!
So here is GBMINI with everything clean – wheels and all (but not waxed, too hot today!)
M&I / GBMINI 
One week of owning the car and I’m already annoyed with washing the wheels so much…of course the white/black combo is well worth the trouble! However I might get a set of Mintex pads, check on recent threads on mini2…cheap and much less dust. I’m just a little weary of the install process. Not something you want to screw up!
I too have been bothered by the abundace of brake dust on my wheels, althought they’re not white, so I suppose that makes it a little better. Anyway, usually once a month or so, when washing the car, I’ll claybar the wheels, then throw a coat or two of wax on them. This produces roughly the same effect that you got, to where the brake dust almost completely washes away when sprayed with a pressure washer. There rest easily wipes away with a cloth.