A suicide door is an automobile door hinged at its rear rather than the front.[1] Such doors were originally used on horse-drawn carriages,[2] but are rarely found on modern vehicles, primarily because they are less safe than a front-hinged door. Being rear-hinged, if the vehicle were moving and the door opened, aerodynamic drag would force the door open, and the driver/passenger would have to lean forward and out of the vehicle to close it. As seat belts were not in common use at that time, the risk of falling out of the car and into traffic was high, hence the name "suicide door".[3][4] Another reason could have been that while a door was open on a city street, a speeding car moving in the same direction as the parked car could rip a front-hinged door off the parked car but someone inside the adjacent seat, even if moving to leave the car, could not get scratched. However, with a suicide door, someone inside or partially outside the passenger compartment would get struck by the suicide door forcefully swinging back to a shut position due to the impact of the speeding car on the door.
Initially standard on many models, later they became popularized in the custom car trade.[5] Automobile manufacturers call the doors coach doors (Rolls-Royce),[4] flexdioors (Vauxhall),[6] freestyle doors (Mazda),[4] rear access doors (Saturn),[4] clamshell doors (BMW) simply describe them as back-hinged doors.[1]