^^ For sure, I’d put the change in the cup holder as well. But if for some completely innocent reason, the change gets lost, or misplaced, or forgotten about, now the guy thinks I’m a crook?
And really, as long as my detailer does a good job, do I even care if he’s the kind of guy who would pocket some loose change? I just want a clean car, I don’t need it cleaned by a saint.
And I don’t care how honest people are - I’m not leaving anything valuable in the car when I take it anywhere for service. It’s not like I’m going to think “Hey, this guy returned my spare change, next time I’m going to leave my Rolex Submariner on the gearshift and I won’t have to worry!”
I guess I just don’t like the idea of putting people through sneaky tests. I prefer just to trust people from the start, until they give me a reason to do otherwise.
Or, if you’re going to do a test like this, just keep quiet about it! Say “Hey, you did a great job! I’ll be calling you again” not “Hey, I made you jump through a bunch of hoops without you even knowing it, and congratulations, you passed my test!” What’s the point? I’d feel manipulated and more than a bit put off.