Assuming police are charging to get your car back then it would probably be quite the profit center for them to enforce in that situation. I would be more concerned about them over enforcing parking infractions as a matter of dept policy, than I would be of parking infractions being ignored.
"We don't have staff so let's pay some other company to lend us staff to do it, for more money that would cost to hire the staff (because their boss needs to earn the living too)"