In most of the US, this type of scam doesn't happen because we don't have this kind of parking lot. I think I've seen just one in my life. Most lots have either parking meters or gates and attendants.
Most lots have either parking meters or gates and attendants.
I don't know where you are from. In Dallas, the downtown lots closest to the center (expensive) had gates and attendants.
Further out (cheaper) were lots where you slid cash into a slot matching one's stall number: a guy came around on a regular basis to collect the cash, but he wasn't stationed in the lot.
