I bought my 2010 Silverado in June and went to get tires rotated as the manual stated and tire shop said they couldn't as the spare was a seventeen inch instead of an eighteen. Called dealer they said call GM. Called Gm they said it doesn't come with the option of 18'. I asked why? No explanation. She asked if it was stated on my window tag. I said no. But i also told her it didn't say I wasn't getting 18" all the way around. case was closed and stated they resolved the issue. WHAT? Has any one else experienced the same issue? And gotten a better resolve?