Automatic license plate readers ubiquitous, including airport parking lots

O'Hare Airport is considered inside the boundaries of the City of Chicago. That includes their various parking lots (deck and remote).

Chicago Police have been scanning plates for years and booting cars that have exceeded the number of allowable outstanding parking tickets or camera violations (currently 2, if they're more than a year old). They also issue City tickets for other violations like expired Illinois plates (ask me how I know this).

The plate scanners also know how long you've been in the lot, so if you lose a ticket and claim you were only there 2 nights when it was really 7...they'll know.

Yeah, the "find my car" thing is nice and I've seen it offered to people, but that's a small aspect of a much larger revenue stream.