Castle Rock, CO
I've taken my Audi A6 to Avalon for a year now, and I could never imagine taking it anywhere else ever again.
Here's what you should expect from Avalon:
1) Accurate, honest quotes. I've never ended up paying more than I expected for any work, which is not common amongst specialist shops.
2) Daily phone calls. I've had a few strange problems, including one that only showed up in the early morning. They got to my car first thing in the morning every day for a week, and called me every day with theories. When it turned out to be a carbon buildup, they found a dealership who could fix it and waived my diagnostic fees for a week of work.
3) Exemplary work. I don't know how they afford Phil, but the front range is lucky that they do. Their work is exhaustive, quick, and expertly performed.
4) Reasonable prices. On some of their work, they're not the cheapest. On some work they are. I don't have the inclination or the desire to get multiple quotes on all the work that needs done to my car, I just want it done right without getting scammed. I've never gotten my car back and wished I'd gone somewhere else, and neither will you.
Really, there is no work these guys cannot do, from full engine rebuilds to ECU tuning to simple maintenance, and there's no one in 800 miles that does it better, faster, and more reliably than them. This is what "5 star" means.