 Entrance to and exit from the car is through the side doors, which lead into the vestibule.When passenger cars are coupled, their vestibules are joined by mating faceplate and diaphragm assemblies to create a weather-tight seal for the safety and comfort of passengers who are stepping from car to car.In British usage the term refers to the part of the carriage where the passenger doors are located; this can be at the ends of the carriage (on long-distance stock) or at the 1/4 and 3/4 of length positions (typical on modern suburban stock).