Have personally worked with Mark and his staff for more than a decade. I can have them perform all repairs on our suburban and my VW TDI. It's tough to reach them somedays but it's worth trying again and again, to get on the schedule. Highest level or Morals and Character I've found in any Mechanic. Never have any doubts on the recommendations and appreciate the consultative approach. In my opinion, Mark is the best performance tuner in Southern MN. Let him tune your HOT ROD or Racecar and you'll know what I mean. Anything from Audi's to Motorhomes, they're competant with it all.