Service Department will take you for a ride if you're not careful.
Unless your car is under warranty or extended warranty, you're better off having repairs done at a reputable non-dealer facility.
Service department wanted to charge 2 hours labor to find source of issue. Next they said oh, something else is wrong, we need ANOTHER hour's labor to find that problem. The 3 hours labor ($100/hr) did not include the parts NOR the labor needed to perform the actual fixes. I was like.. Here's your 2 hours labor and give me my car back.
As the issues they found were fixed in the past by another Chevy dealer the prices quoted by Courtesy to perform fixes were exponentially higher than what I paid in the past.