Have you tried a wheel clener and a decent brush? Try Wonder Wheels which you can get from Halfords.
Are they white or silver?
Red/Black R56 Cooper
Stripes, CHILLI, ASC+T, MINI HiFi, Piano Black Dash, Red Colour Line, Heated Mirrors/Jets, Spare Wheel, Smoker Pack!
Mods - Cooper S pedals, Cheqered interior mirror, chrome side repeaters
1. Give the wheels a reasonable clean to remove the worst of the dust.
2. Apply some white spirit to a clean rag and wipe off the rest of the dust visible. Don't go too overboard on the white spirit though!
3. Give wheels another good clean. This time I use one of those bug removing sponges (bit harder than a normal one but doesn't scratch the paint).
4. Dry the wheels off and then apply some wax to the wheels by applying to the cloth not spraying onto the wheel itself!
After this the dust cleans off easily each time i wash the car (once per week) using the bug sponge on the wheels. So far i've only waxed the wheels twice in the 6 months i've had the car and my wheels look great! Although i find tar spots more stubborn to remove than brake dust.
I don't know availability in the UK, but in the US one can buy aerosol brake cleaner in an auto parts store that should help. It is a solvent with aerosol pressure behind it. You should re-wax your wheels after. Regular cleaning to prevent the build up of course is much better.
This stuff does an excellent job, just spray it on cool wheels let sit for 30 seconds and spray it off and you have almost nothing else to do.
( just be carefull it's VERY nasty stuff... started eating away at the driveway... )
Liquid Yellow Cooper
SunRoof, DSC, Sport Seats, H&R 27mm Front - Progress Rear 22mm Sway Bar, Chromed fixed Upper and adjustable Lower Control Arms, Ultrik Air Intake, Stebro Exhaust, S Hood Custom air intake, StopTech BrakeLines, SPAX RSX Coilovers
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