Car door

Doors most often integrate side windows for visibility from inside the car and can be locked to secure the vehicle.

Also, they may be operated by remote control, with the transmitter often integrated into the main vehicle access and a key for the ignition.

As late as the 1970s, some vehicles used exposed push buttons to operate the door latch, such as certain Opel models.

A death that occurred exactly that way led to the landmark legal case of Daly v. General Motors Corp., 20 Cal.

The court affirmed the right of General Motors to introduce evidence that decedent Kirk Daly flew out of his Opel not only because the door popped open, but because he was intoxicated and not wearing a seat belt—but in the same opinion, reversed and remanded for retrial because the jury had not been instructed on the then-rapidly developing doctrine of comparative fault and there was a high risk that the jury may have improperly applied the doctrine of contributory negligence to treat such inflammatory evidence of the decedent's negligence as a complete defense.

In the past, certain retracting windows were operated by direct (up or down) pressure, and were held in the up position by friction instead of by an internal lift mechanism.

Hatchback and estate or station wagon vehicles are typically described as 'three-door' or 'five-door' models in Europe and some other parts of the world.

In the case of saloons or sedans and coupés, the boot/trunk lid is not counted as a door by definition because it is for a separate storage compartment - these cars are marketed as 'two-door' or 'four-door'.

The openings used for cargo access are generally described by their function - such as hatch, tailgate, or liftgate - depending on the vehicle design.

For example, a "two-door hatchback" will have two side doors for passengers and a rear opening to the cargo area.

[3] Similarly, a station wagon or SUV can have four-doors since the opening to the cargo area via the rear tailgate or a hatch is not counted as a door.

A canopy door sits on top of a car and lifts up in some way, to provide access for passengers.

Various countries are members of these regulations, for instance, Australia, Canada, European Union, Japan, Russia, and the United States.

Application of this requirement is done for instance by the European Union, Russia, Japan, New Zealand and Egypt.