Ive just read the Multispokes post and thought Id share a little tip with you poor sods (like me) who have difficult wheels to clean.
Brasso is the answer.
Pour some into a small bowl and paint it onto your wheels, leave it for a little bit and then wash with some warm water.
Also...if you ever have trouble getting tar off your paint work, just dissolve some brasso into a little watter and use a soft sponge or cloth on the tar...comes off nice and easy.
Well there ya go...my christmas pressie to you