Mafia III

This achievement can be earned at any time during your playthrough. Police cars are easily identifiable throughout the city since they appear as large blue vehicle icons on the mini-map.

The easiest way to steal one is to cut it off in traffic, exit your vehicle, then approach the Police car's driver side and hold to hijack it. The cops will obviously become hostile and begin to shoot you, but the achievement will unlock shortly after you're behind the wheel of the car.