pillar

The pillars on a car with permanent roof body style (such as four-door sedans) are the vertical or nearly vertical supports of its window area or greenhouse—designated respectively as the A, B, C and (in larger cars such as 4-door station wagons and sport utility vehicles) D-pillar, moving from front to rear, in profile view. Nomenclature Car pillars are vertical or inclined components of an enclosed automobile's body that both support its roof and reinforce the torsional rigidity of the body. An alphabetical convention for designating a car's pillars has developed over time, used variously by the automotive press in describing and reviewing vehicles, insurance companies in identifying damaged components, and first-responder rescue teams to facilitate communication, as when using the jaws of life to cut their way into a wreck. The letters A, B, C, and D are used (in upper case):