We experienced one of those mechnical problems that really stumped the mechanics at Advanced Autowerks.
Details aside, while it might be the case we ended up spending money for work done unnecessarily, it has to be said that the they kept at it until they actually figured it out. While we had to tow the car in the first time, after they had thought it was fixed and we drove it home, when it again wouldn't start, they quickly sent someone over to professionally tow it again, no charge.
Though it was frustrating both for us and for them (it took over 2 weeks to finally get it fixed), they were kind, considerate, sympathetic, offered us the use of a car (but we could get by without it), and did not nickel and dime us. They kept us informed as best they could.
The first fix was costly, but for the subsequent work and actual or final fix, there were no additional charges.
We ended up with them when our long-time mechanic recently retired. Our 2002 VW Golf TDI has over 100k miles on it.
I can Not imagine what this experience would have been like at a less reputable garage.
They now are definitely our regular mechanic.