This happened to me two weeks ago. I took my car in to get the oil changed, and this guy pulls out this nasty air filter from the desk and claims that it's full of ratshit and it'll be making me sick etc etc. I change my air filters in the Canadian Tire parking lot like every other Canadian, so I walked up to my car, popped the hood, and pulled out the air filter.

"Oh no, it was the other one." Popped open my glovebox, pulled it out, and inspected it. Clean, because they're $10 (and I change them when I change my clocks and test the smoke/CO alarms).

So fuck that asshole. He wanted $80 to change them or some shit. Probably makes a lot of free money that way. Fuck that asshole.