Since you cannot eliminate the offending parties, at some point you gotta ask yourself how much your time is worth and if you actually give a damn if they get their fricking $91 dollars.
Just look at how many peoples’s time have been spent on this thread alone.
Pay them or don’t - I vote DON”T, then go back to living your life.
Have to address it.
Could happen again
Paying the fricking $91 would not end his troubles. He may have to pay tickets in perpetuity if the car is in his name and some asshole keeps getting parking tickets; or even worse, uses the car in commission of a crime, or runs over somebody. He would do better to report the car as stolen. If he's gonna be rung up for tickets on the car, it may as well be in his possession.