A vehicle door shell is the metal frame of a car door. It includes the door panel, window regulator, and weatherstripping. The door panel is the inner surface of the door that faces the interior of the car. It is usually made of plastic or vinyl and is attached to the door shell with screws or clips. The window regulator is the mechanism that raises and lowers the car window. It is usually operated by a hand crank or switch and is mounted on the inside of the door shell. The weatherstripping is a seal between the door panel and glass that prevents water and air from entering the car.