When the Michelin Man cops are parked outside the KFC, the Ghostbusters "No Ghost" logo Stop sign is facing them with the ghost's head on the left (as it is customarily displayed in North America). When the cops pull away, the sign is shown from the other side, and the ghost is still facing the same way. When seen from the other side, the ghost's head should be on the right - as seen later on when the the Esso Girl and Big Boy are getting into the abandoned cop car.