You may want to look into a wheel wax if you haven't already. It should cut down wheel cleaning time substantially.
My favorite wheel cleaners are Auto Finesse Imperial and Sonax Wheel Cleaner.
Regardless, I find myself scrubbing a little every time I wash.
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F80 M3 DCT|Alpine White . Black Leather | My Build Thread
E90 M3 DCT|Melbourne Red . Speed Cloth | My Build Thread
E46 M3 6MT|Jet Black . Black Nappa Leather | My Build Thread
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