I think car wash soap and water is best. When you let the wheels get so dirty that this isn't enough, and then need something stronger to clean them, I think you're heading down the wrong track, especially since many owners have complained that the OEM wheel finish isn't very durable. I generally wash the car/wheels every other week or so, and have the Axxis Ultimate brake pads which are somewhat less dusty than OEM. I find that soap and water and a small sponge works fine.
Be careful with wheel cleaners. I own a 1.75 year old cherry M5. The car has NEVER been in a car wash and has only been cleaned by BMW dealers and myself (and I never use anything stronger than cold water on the wheel rims). The last time the car was washed by a BMW dealer (who DENIED they ever use acid on the wheels), the wheel finish was ruined on 3 wheels ... the lug nuts now look like they are 100 years old and two of the Roundel inserts are peeling (the car isn't 2 years old, yet). I am negotiating for new wheels, tires (I almost need them), Roundels and lug bolts for about $3,500 (best price I can get from BMW). Ouch, and **** ... BE CAREFUL and don't use anything stronger than absolutely needed on the rims ... Just my free advice ...
I agree with Quick M5. The gun smoke finish on the stock rims is VERY
fragile. When I bought my '03 M5 last year I didn't notice that the rims
had black drops and rivlets all over them. When I returned to the dealer
he explained that this may have been caused by road spray when the rims
were hot (highly unlikely). I suspect that the detail shop sprayed the wheel
cleaner on and forgot them. Result was the dealer replaced all four rims.
I now only use mild car wash soap, a very soft brush and water on
cold rims. Using Zaino on the rims really helps keep the brake residue from
For non gun smoke finish rims I use Eagle One All Wheel Cleaner.
It's cheap and really gets the brake dust off. For a complete treatise
on the subject of wheel cleaners, see Guru Reports (www.gurureports.org).
Bmw wheel cleaner....yeah it acually works, spray the wheel off with water spray this on let it sit a min then spray it off wipe with a towel, and looks great.
The other...go to the store get pure amonia, get a spray bottle, load a little dawn into the bottle about a squart, then about half of amonia, and the rest with water, shake and clean the wheels with that the same as above works great.