At 6 am every morning our local police department would have two officers take a patrol car out with a Mannequin in full police uniform in it. They would park it somewhere in the city for the day. The Mannequin was named Raymond, and I listened to the police scanners as part of my job, and you would hear two officers radio in that they were out on "Raymond Duty". Eventually some private citizens would seek out where Raymond was parked and leave notes under the windshield wiper, or snacks like a donut. As far as I know, Raymond has been retired.
I have a neighbor around the corner that lives on a busy street. He has an old California Highway Patrol SUV that he parks on the street. Still black and white. His neighbors say they love to watch people suddenly slow down when they see it parked, thinking it is a still in service patrol vehicle doing radar enforcement.