Which component forms the sides of a vehicle's body behind the side doors?

The quarter panels are the components that form the sides of a vehicle's body behind the side doors. They are critical structural elements and typically encompass both the outer body and the rear wheel well area. In vehicles with a more traditional sedan shape, the quarter panels extend from the rear doors back to the rear bumper, providing not only a structural framework but also contributing to the vehicle's overall aesthetic appearance.

Additionally, quarter panels often house components related to the rear lights and can hold the rear windows in place in certain designs. Their position on the vehicle is significant for allowing easy access to the trunk and enhancing side profile designs.

While fenders are located over the wheels, rocker panels are found along the sides of the vehicle at the bottom between the front and rear doors, and sail panels are the vertical sections at the rear of the roof, none of these serve the specific function or location of the quarter panels.