Based on reviews from here on Yelp and Audi owner bulletin boards, I took my 2006 A4 here for needed maintenance and repairs. I have been using, perhaps stupidly, an Audi dealer for all service and maintenance for all these years. The Check Engine light went on and the dealer informed me that repairs could cost upward of $2,500 - since there was no way I was sinking that into a 10-year old car, I started shopping - sadly - for new cars. I figured it was worth a second opinion, so I made the trip to GCD - and was I ever glad I did. The entire experience was outstanding - from the initial greeting, to the no-BS way they describe to you what they are going to look at, what they will try to do, how long it will take, and how much it should cost. Full transparency, honest advice and guidance, great feedback throughout the process. My story had a happy ending - the repair was done, plus scheduled maintenance, plus A/C recharge (1st time in 10 years; can't complain) for a fraction of what the dealer would have charged. And they showed me the diagnostics for the car - told me it was in excellent shape and that I should deb able to drive it for many years to come. A huge relief. GCT is a service organization that is highly professional and as meticulous and fussy about servicing German automobiles as I am about owning and driving one. Count me as one happy new customer - who should have gone to see them sooner!