Reading some of the comments brings me back to basics.
I bought a 2001 SLK 320 with 61000 km in April. I never considered taking anywhere but to my dealer who services my E Class wagon.
The techs know the car, have tremendous resources behind them and if I can, I buy parts on line and just pay the labour. Peace of mind, no hassles and they meet their deadlines. Why bother with an indy if you can get great service from the dealer. Labour costs are not always the way to go.
The problem with the dealers here are that they want the car for the whole day no matter what the issue and how far in advance you schedule. The dealer service also insulates you by having you go through a service advisor and never speak directly to the technician/mechanic. I am not sure what training the service advisor has had but it seems if I get technical; they look bewildered.
The indy I use specializes in MB, is involved in local racing (an MB) displays all his staffs training certifications, discusses technical issues with me, advises on parts options and why, and brings out my replaced parts for me to examine. There is no sparkling lounge with free coffee and car wash but I bring the car in at the scheduled time and the car is ready as soon as the estimated labour hours are expired. I prefer to wash it myself and I don't drink coffee. The technician who performed the service will advise on anything he/she found and give DIY advice when I ask (as long as it doesn't take long). The convenience of having my car back in an hour or two is why I started using the indy and the other reasons are gravy.
PS. May as well plug my indy Henneken Auto. Six or seven techs and very nodern equipment. Hans Naes (the owner) is the meet/greet/cashier/service advisor and master tech. I enjoy discussing issues with an owner who has such pride in his business that he is the customer service rep!
Conversations go like this: "Ve use only ze finest MB parts because zis is vat MB recommend. Your brake pads und disc will look like zese. If you vant to see the actual brakes ve vill use, ze truck vill deliver in a few minutes." I wait 5 minutes while the car is hoisted and wheels removed and he shows me the new brake parts. When I return in an hour he shows me the old brakes and takes a caliper to them to measure how far past spec they are. The oompah band starts up, we don lederhosen and break out the lowenbrau to celebrate and ... (maybe I am getting too entheusiastic).