A station wagon, also called an estate (UK) or simply wagon (US), is an automotive body-style variant of a sedan/saloon with its roof extended rearward over a shared passenger/cargo volume with access at the back via a third or fifth door, instead of a trunk/boot lid. The body style transforms a standard three-box design into a two-box design — to include an A, B, and C-pillar, as well as a D-pillar. Station wagons can flexibly reconfigure their interior volume via fold-down rear seats to prioritize either passenger or cargo volume.