I've been using KMC for years. I first found them after another "highly respected" Boston area independent Porsche mechanic rebuilt my 993tt engine and after 9 months returned the car a complete and barely driveable disaster. Tim and his team worked with me to sort out the suspension, steering, engine and turbo oil leaks, replace all the original and very questionable rubber which EPE had just slapped back on, etc, and got the car sorted out again. Including finally fixing the problem of cylinders filling with oil and blowing clouds of smoke on startup, which had been the reason for the engine rebuild at the earlier mechanic.
KMC's attention to detail is incredible, the shop is the cleanest and most organized I've seen, they are all super friendly and enthusiastic car nuts, and you can work directly with the mechanics to understand what your options are and decide on a plan forward. Low pressure and no ego to get in the way of straight talk about your car.
My husband and I have serviced our track-prepped Caymans here for the past few years. We are always impressed with their knowledge, level of service, and respect for us as customers. They get it right the first time!
I can't recommend KMC enough. I brought my e46 M3 ZCP in for a 60k service and a new short shifter, based on the recommendation of another friend who brings them his M Coupe. I worked with Tim and Edwin -- they're both great, honest, and knowledgable guys. They care about what they do, the cars they work on, and the clients they serve. They gave me back a totally different car than then one I dropped off with them - between the valve adjustment and the short shifter, it was a night and day difference. I had a smile plastered on my face the whole way home, and still have it a few months later. I can't wait to bring it back to them for the next thing (suspension?).
On top of that, they gave me a great 50mpg TDI (with a sport suspension!) loaner car, *and* they cleaned my M3 before they gave it back. Class acts.
Oh, and just walking through their shop is worth the trip -- there are always a bunch of awesome cars. And they sit in the cleanest working space I've ever seen.
KMC....expertise at its finest. The guys at KMC are true masters in the craft of automotive engineering and salesmanship. Tim and David are true wizards when it comes to anything mechanical while Jason is knowledgable beyond belief when it comes to the car you want and locating it as well. I advise all my friends to take their cars to KMC from simple service to track builds and anything in between. KMC 5 stars!