Overall I've been a very happy customer at Williams Auto World. They have taken care of me on more then one occasion. From my oil changes, to my brakes squeeling, they were very attentive and made sure everything was right when I was going to pick up my car. Well I went in for my before 50k checkup at 49.5k, and found that I had a rear differential leak, and a coolant leak. Well, thank god i went before my 50k for this check up even though it meant paying some extra money for them to check, since its a relatively big problem. At any rate, everything is good, they give me a shuttle ride back to campus so I can attend class and what not. At the end of day, when my car is ready, I picked it up and left happily, and hoping the a4 won't give me too many more problems after the warranty. At any rate, the next day when i was driving, I thought i heard some wierd noise when i accelerate, but I didn't take much note of it afterwards because I got on the freeway to go to school. Then I forgot about it, and didn't hear anything to remind me of it. At any rate, i booked an appointment with Stefan at GMW the week after to balance some wheels, check for shitty gas mileage, etc etc, and I heard the noise again, and it was much more apparent. Thanks to Ron and Stefan, we figured out that my rear differential was actually LOOSE....When i mean loose, i mean we could push it up and down, and another screw on a horizontal link was loose as well. I became pretty furious, and immediately called Williams Auto World about this case. On the same day, I decided to blow two coilpacks when I got home. So i called Williams Auto World and they said Tow it in, and they'll take care of me. At 50.5k miles they good will warrantied two coilpacks, and they did not mention anything else about the rear diff...I guess i got a good will warranty out of them neglecting my rear diff...Sigh. Overall, I trust this place, but if you are a handyman of any sort, I would just double check to make sure they did everything right. But as of right now, it seems all audi dealers in our general area is the suck.