If riding as a single officer and you’ve execute a traffic stop, you might consider using this technique to fool the stopped occupants into believing you’ve got a partner. This is really only effective during low-light stops when it’s harder — if not downright impossible — for people in the stopped vehicle to see you. When you exit your vehicle and close your door, open it and close it again. Another option is to open and close your door, then circle behind your squad and as you walk past the passenger door, open and close it, then make a passenger-side approach. Oh, and it’s also kind of vital that the subjects in the car aren’t blasting a radio at 100+ decibels. If they are, no such door-slamming trick is going to make a difference.