Have you tried Simple Green and a small scrubbing sponge? Let it soak first. You might look for the Simple Green foam for autos and bbq grills. I rarely get tar buildup, but it works like a charm on the toughest of brake dust deposits. I usually just need some car wash and the sponge.
Bought the BMW wheel cleaner and it's useless. Same with their brush.
Bought the BMW wheel cleaner and it's useless. Same with their brush.