Car Three-box styling Explained
Three-box design is a broad automotive styling term describing a coupé, sedan, notchback or hatchback where — when viewed in profile — principal volumes are articulated into three separate compartments or boxes: engine, passenger and cargo.
Three-box designs are highly variable. The Renault Dauphine is a three-box that carries its engine in the rear and its cargo up front. The styling of the Škoda Octavia integrates a hatchback with the articulation of a three-box. This style was later used by its larger Škoda Superb, which marketed as the TwinDoor, within the liftgate operable as a trunk lid or as a full hatchback. As with the third generation European Ford Escort (also a hatchback), the third box may be vestigial. And three-box styling need not be boxy: Car Design News calls the fluid and rounded Fiat Linea a three-box design — and most examples of the markedly bulbous styling of the ponton genre are three-box designs.
One-box design pulls the base of a vehicle's A-pillars forward, softening any distinction between separate volumes and enclosing the entire interior of a vehicle in a single form — as with the 1992 Renault Twingo, third generation Chrysler minivan or Tata Nano.
The one-box design is also called a monospace or monovolume configuration.
Two-box designs articulate a volume for engine and a volume that combines passenger and cargo volumes, e.g., station wagons or (three or five-door) hatchbacks.