I brought my 2014 CTS-V which I had purchased from them in for service. I had it towed down because of a horrible squealing and shaking coming from the rear of the car. I got down there to pick up a loaner car while they looked at my car and noticed my car being pulled into the service area. After standing around awkwardly in the service area trying to figure out where I needed to go I finally asked the guy that drove my car in and he told me I needed to talk to Chris in a rude manner and walked away. Now I'm standing around awkwardly in the service area trying to figure out who Chris is. So now I'm standing awkwardly in the office not knowing what to do. Finally the infamous Chris shows up and I tell him my name and my car and he immediately tells me it's my aftermarket exhaust causing the problem. I had to argue with him that it wasn't the exhaust and show him the video I took of the sounds it was making and he still stuck with the exhaust being the problem then he sent me to another service manager, I have no idea who he is because he never introduced himself. Here's the main issue I have, when I called and set up the service I told them that the shaking and squealing didn't start until 60-70mph. I get in the car to take the new guy for a ride and let him hear the sounds and I notice the odometer is only 1 mile more than when I had it towed. Somehow this service dept. was able to diagnosis my problem that only happens at 60-70 mph with out even driving it.
If you are female and go to the service dept. be weary and don't let them treat you like less than a person because they think they can spit out some information and have you believe it. The entire time I was there no one ever greeted me or asked me if they could help and that's basic customer service, if you hate your job as much as it seems maybe customer service isn't your forte.

Just to update I took my car to a different dealership and they replaced the rear differential under warranty, these guys let me drive my car an hour home with a broken rear differential. I would never recommend this place and I will never be returning.