Dealer just installed a set of ifg wheels and they look great on the car. After I ot home i noticed that there seems to be "water stains" on the 2 wheels on the drivers side. Seems like soapy water dripping down the wheel dried up slightly lighter in color than the wheel. When I tried to clean this it seems to be a permanent stain (or discoloration). Anybody knows what can cause this? The dealer cleaned my car after installing the wheels. Anyone knows how to fix it?