I've had my Cooper 6 months now and the white wheels do get dirty. living in the fens, probably a bit dirtier than you city folk will find! But i dont think they get dirtier quicker or more noticably than silver wheels do. However, recently i have noticed small marks appearing on the wheels if i look closely. I'm not sure if i can get these marks off or not. When they've just been washed they do look the 'dogs' though!! if getting a Mini with white roof and wing mirrors i'd recommend getting white wheels too. (check out my pics in the personal gallery: AV51HCC)