(I work in a tire center. Two shady figures show up at the door in an old, battered van:)

Guy #1: "Are you interested in second hand wheels?"

Me: "In some cases, yes. What do you have to offer?"

Guy #1: "I have in my van a set of 18-inch alloy wheels for a [luxury German car] with new summer tires." *he then opens the rear doors and shows me the wheels*

Me: "Oh, they're quite nice! In fact, I have a customer who's looking for these kind of wheels for his car. Let me call him. I guess he'll be more than happy to make a deal with you!"

Guy #2: "Good. Can we wait inside?"

Me: "Of course, and please help yourself with some complimentary coffee while I make a couple of calls."

(15 minutes later, the customer showed up... together with two cops who handcuffed the guys and put them in the back of their cruiser. Apparently, it is not only a bad idea try to sell stolen wheels, but even a worse one try to sell me the very same wheels and tires I installed the day before on the [luxury German car] of a loyal customer!)