I'm having 'chipping' problems with my 06 (32K miles) gunmetal wheels. All four wheels are showing signs of corrosion. Never hit a curb and never use anything to clean them except soap and water. I took it to the dealer and they agreed to do a "one-time replacement." However, they also noted that this problem will re-occur with the new wheels if I drive them in the winter. (Michigan roads) They say that the wheels are not "all season." I've contacted GM customer care and emphasized that there should be a permenant fix to this problem -not just a temporary band-aid. Anyone else having this problem? I'll keep you posted w/ the result from GMCC.