The service department is horrible, they lie, cheat and steal. They are worse than salesman. They have told me my oil was changed only to stop a mile down the road and check and it's still dirty. Why? I truly don't understand why they would do this. There have been multiple times while waiting on my car, I've heard mechanics say I didn't do it. Once was in reference to changing a fuel filter, the next rotating tires. These are all services customers pay for. I'm disgusted and appalled. I will be taking my business back to GMC. I also plan on doing something about the fraud the service department is partaking in.