The roof support structure on either side of the rear window on a typical sedan or coupe. It corresponds with the A pillar located on either side of the windshield at the front of the car and the B pillar which sits between the front and rear doors on a typical sedan. In SUVs, minivans and wagons with extended cargo areas, the C Pillar is the vertical structure behind the rear door while the vertical supports at the rear of the vehicle are called D pillars.
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