Mine do as well... Its the heat of the calipers combined with the dust and the wheel cleaner. Its rare that calipers can stay shiny unless they have a smooth coat on the outside and even then....
I'm Brick Tamland. People seem to like me because I am polite and I am rarely late. I like to eat ice cream and I really enjoy a nice pair of slacks. Years later, a doctor will tell me that I have an I.Q. of 48 and am what some people call mentally retarded.
2010 Chevrolet Camaro SS - Daily Driver
2008 Chevy Silverado 2500 HD LT 6.0 - Tow Vehicle
1993 Volkswagen Fox - Race Car (yes seriously)
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