i think i also have similar issues with my wheels. They kind of look like dripping water marks and spots. The are like greyish / whitish in color i guess. I get them all the time when i try to use wheels cleaners. I used neverdull to take it off and it worked perfectly... Take a shot at it...
they have it at autozone and other car part stores..
2010 AW/BLK 135i
VM 6465 Single Turbo, JB4 + MHD, VRSF CP & Tial, Big Tom, Fuel-It PI + Stage 3 + Return + Ethanol Sensor, BMW PE, MFactory LSD, Spec 3+ & MFactory SMFW, RB External PCV
Best stock turbo 12.5 @ 19.46 spinning all the way down
RIP 2008 AW/BL 135i