One doesn't expect too much from Canadian Tire, but it was time for my Drive Clean test, and I was there, so I thought, "Surely they can't screw that up."
I thought wrong. As I was waiting outside the service area, I heard an engine screaming like I was at the Indy 500. After 10 or 15 seconds, it stopped, then started shrieking again. I walked to the door of the garage and there was my car sounding like it was about to explode.
The pinhead doing the test had connected the car to the Drive Clean computer incorrectly, and it was repeatedly racing the engine at twice the usual speed.
Maybe it was just this one guy, but it's kept me from ever taking my car to any Canadian Tire garage.