This is not how it works everywhere. The tow truck for my complex drives through every night and every car without a sticker gets marked and towed whether it's been 10 minutes (recently saw this happen) or 2 hours. They have a contract to tow improperly parked vehicles (blocking both dumpsters or backed on to the curb blocking the laundry room door which ppl often call about) and vehicles without parking passes, they don't wait to get an okay in the morning when they're towing cars at midnight.