I do hope you succeed. Congratulations on repairing 1000 cars. What sorts of repairs were they? If you pay your mechanics so well, how does the business itself make any money? Other questions that spring to mind: What equipment do they have, what repairs do you specifically avoid, How do you source parts, what happens to flat rate when the part is wrong? I looked at your website last week and don't recall seeing this information.
I have not met a shop yet that hasn't had a ridiculous customer complaint. You seem to be lucky, for the rest of the industry it is always 1% that drives you crazy. By that math you should have had 10 unreasonable customers by now. I also believe that people are inherently good. I did $2,000,000 in sales of $50 tools with Snap-on and only ended up with $6000 in bad debt on what where essentially handshake deals. A loss of $3 per thousand.
Also if you would like to have a non-public discussion, you can email me at gregpilling @ gmail.com