I will tell you a few first hand stories from Khasakstanian Tire, and explain to you why I am scared every time I see a car go into, or come out of these stores.
My first car was a 1985 Volkswagen GTi, and I was getting a PPI done at their Stoney Creek, Ontario location. The monkey was going through a checklist and found a hole in the driver's side floor panel. He told me that I should get that addressed, but would still be safetied. Several minutes later, he goes into the back seat, and sees there are only lap belts installed and that they need shoulder restraints for all seats for all vehicles. When I ask him where exactly these were to be installed because there was clearly no mounting points he shrugged and just said "I dunno, you need them though" Somehow, I talked to the manager and got the car safetied after all.
Several years later, they had a special on some BFG all season tires and seeing as my lady needed new rubber-we decided to go to the Upper Gage store in Hamilton, Ontario. I spoke to the girl at the counter and asked her to be sure the tech uses a torque wrench to reinstall the wheels. Not more than two minutes later, the "gentleman" flies out of the service bay and confronts me. Pretty much verbatim, the conversation went like this;
He asked me "Why do you want these put back one the car with a torque wrench"
I said "Because that's what the manual tells you to do" hoping to avoid a protracted confrontation.
"But we put them on with an impact wrench, and they go tight enough"
"I am sure they do, what torque does it install the lugs to"
"About 175 ft-lbs, like I said, plenty tight"
"Number 1, the manual says 85 ft-lbs, so you overtighten the lugs by a factor of two, and number 2, have you ever had a flat on the side of the highway"
"Yeah"
"Have you ever had a wheel that you couldn't get off?"
"Well, yeah..."
"So what do you think she would do, if YOU couldn't get the wheel off?" As I point to my fiancee.
"..."
"put the wheels on like I said."
After these two instances I have not, nor do I plan to return to their auto service center. That is, unless I get my NSX from the states. They seem to hire only the service guys that the other chains and shops slough off and won't hire.