We've all been there (well, maybe most of us have). Your car is broken down in an unfamiliar locale and you have to confront the fact that you are at a mega-disadvantage when it comes to your relative level of knowledge vis a vis the mechanics.
It is my hope/belief that the arrival of technologies such as social, mobile, and user-generated content sites will change that.
Part of that is making sure that people know you are holding them accountable. Here's how I did it with Elite Automotive in Potomac, MD. Their willingness to go on video showed me their trustworthiness and then, of course, I validated it with my trusted mechanic (unless they are in cahoots with each other :)
Seriously, these guys were great and I highly recommend them...even when your car isn't broken.
Enjoy the videos