I brought my car in for a check engine light covered under a factory warranty. Service technicians could not figure out the problem, after letting it sit in the shop all week. The did find time to take my car for a joy ride which was clear to me by the extra miles, filthy interior carpets and mud on the outside of vehicle. I detailed the car before dropping it off. Also, when I picked up the car and turned it on, they had turned my stereo volume ALL of the way up and it almost blew out my speakers. If you are actually trying to diagnose a legitimate engine issue, you would be listening to and feeling the engine and how its idling, not blaring the radio. Not impressed and wouldn't feel safe leaving my car there again.