Talked to my dad, who's a cook county police officer. He said that they run the plates of the car, find the house it belongs to (if in the area) and have them move it. If the car owner is not home or lives too far away, they'll smash the window and run the hose through it.
If they move the car, they get a ticket for parking there.
If they dont/cant move it, they'll spare them the ticket, but run the hose through it. Not a cent from the city goes to the owner.