Molto meglio la versione inglese in cui viene spiegata l'origine del nome (cpoupé = tagliata, riferendosi alla coda corta o assente)
A coupé (French word from the verb couper to cut) or coupe is a car body style with a close-coupled interior offering either two seats or 2+2 seating (space for two passengers up front and for two occasional passengers in the rear). Through the 1950s convertible models were sometimes called convertible coupés, but since the 1960s the term coupé has generally been applied exclusively to fixed-roof models. Coupés generally, but not necessarily, have two doors, although automobile makers have offered four-door coupés and three- and five-door hatchback coupés, as well. Modern coupés generally have the styling feature of frameless doors, with the window glass sealing directly against a weather-strip on the main body.
The SAE distinguishes a coupé from a sedan (saloon) primarily by interior volume; SAE standard J1100 defines a coupé as a fixed-roof automobile with less than 33 ft³ (0.93 m³, 934 L) of rear interior volume. A car with a greater interior volume is technically a two-door sedan, not a coupé, even if it has only two doors. Some car manufacturers may nonetheless choose to use the word coupe or coupé to describe such a model, e.g., the Cadillac Coupe de Ville.
In some parts of the world (especially America), it is becoming more of a marketing term for automotive manufacturers, calling any two doors (or three door) a coupé. This is mostly due to the fact that coupés in general are seen as more sporty than sedan, hence a coupé would be perceived as sportier than a 2-door sedan. Lately, some four door sedans are being marketed as coupés, notably the Mercedes-Benz CLS-Class. Marketing divisions from other companies are set to follow the example of Mercedes; for example Audi with its rumoured 4-door coupé variant of the upcoming A5. In other locations (in particular, Australia, the UK and some of Europe), the traditional 2+2 seating definition persists among the general public.
alla voce sedan si trova questa immagine, molto chiara:
in cui si capisce che è improprio chiamare coupé un'auto in cui i 3 volumi sono nettamente separati, dato che la forma del padiglione non realizza alcuna "continuità".
quindi diciamo che:
- altezza del padiglione
- coda più o meno lunga
- andamento dei volumi
permettono di dire con chiarezza cosa è e cosa non è una coupé.