Best bet is to whip them off the car, clean, clay etc and get them so they look brand new. Then apply some wheel armour. It's the best stuff you can use. Your wheels are always going to get dirty, but this should keep them cleaner for longer, and not only that, EASIER to clean when you do come to clean them.
I'm gonna run a test with this product on a car I look after which does high motorway mileage