The pillars on a car with permanent roof body style are the vertical or nearly vertical supports of its window area or greenhouse—designated respectively as the A, B, C and D-pillar, moving from front to rear, in profile view.

A sedan or saloon is a passenger car in a three-box configuration with separate compartments for an engine, passengers, and cargo. The first recorded use of sedan in reference to an automobile body occurred in 1912. The name derives from the 17th-century litter known as a sedan chair, a one-person enclosed box with windows and carried by porters. Variations of the sedan style include the close-coupled sedan, club sedan, convertible sedan, fastback sedan, hardtop sedan, notchback sedan, and sedanet.