GMC has the worst customer service!!! they refuse to fix my car, and laugh at me when i call, they lie, and tell me there is NO ONE i can complain to.. the tell me that this is the way the vehicle runs, when i have test drove three others, and they DO NOT have the same problem!! i will NEVER BUY A GMC in my life time again!!! i am in the process of finding an attorney that will handle this case for me