I had a great experience with their service department. I bought a used CTS-V from a local high end used car dealer. There was a slight grinding in the rear end that I thought a simple fluid change would fix. I made an appointment at Coulter a couple days after I bought the car for the fluid change. A couple hours later, after changing the fluid, they let me know that it needed a new differential. The car was still under the 5 year warranty. They didn't have an extra loaner, so they pulled a car off the lot with 11 miles on it for me to use. The door sills were even still wrapped in plastic. The same part had been on backorder for another customer two months. I drove the loaner for several weeks while I waited for the part to come in. Gary Shimp, my service advisor, gave me a call when the first customer's part did come in. Mine followed a week later. When I picked my car up, I wasn't charged for anything. Even though I had never been a Cadillac customer before and I had recently purchased the car used, Coulter, stood behind the warranty without any question. I will definitely be a repeat customer.