It really doesn't get much worse than this.
Car was taken to this dealer while I was out of state, as I accidentally sucked paper towels into both intakes, and didn't have the means available to fix it myself, and there wasn't an Indy shop around that would touch it.
Hixson had my car over two weeks before they even pulled it into their bay, during which time I flew home and drove a rental, and when they were finally done they said a sensor was broken and needed to be replaced. It was a $100 t-map sensor, and they wanted to charge me $400.
I told them absolutely not, and they said that was fine, and that the car was fine to drive home (over 300 miles) and I could replace the sensor when I got home.
Their parts department didn't have a sensor in stock, and no other dealers within 100 miles had one in stock either. I had already burned enough work from home days on this that I couldn't order one online and wait, either, so I drove home in limp mode.
When I got home I found they had broken the wiring harness for the sensor, and upon fixing that the sensor worked fine, but then I discovered that they hadn't performed the work invoiced.
I ended up cleaning the paper towels out myself, by renting a lift, and had to file a dispute with Citibank to get the nearly $600 they charged me back. Hixson stopped all communication with me when I sent them pictures of the wiring harness.
Horrible, shady dealer; avoid this place.
More details on this nightmare can be found here:
http://www.georgebelton.com/HixsonBMWofMonroe.php