Throughout the 20th century coupés have been identified as the club, business, opera, sports, 4-door, quad and combi coupés.
A common pre-1950 coupé was business coupé designed specifically for traveling salesmen who sacrificed the rear seat for extra trunk space that reached into the cabin of the car.
The popular prewar club coupé was equipped with a full rear seat and considered sporty for its time, but it's not considered a coupé today because of the pillars behind the doors.
By the 1950s, the coupé lost its pillars with the roofline becoming flatter and the doors designed without window frames.
The sports coupé, also called the berlinetta, became popular following the introduction of the Ford Mustang 2+2 fastback for its sloping roofline to the rear deck.
In recent years the quad coupé has emerged with one or two half-size rear doors on pillarless cars, while Mercedes-Benz is marketing its CLS series as a 4-door coupé.
The definition of the coupé automobile has evolved over the last 100 years to mean many different things depending on the automaker, the designer and the whims of the marketing department. The coupé, properly pronounced "koo-pay" but shortened to "koop," literally means to cut, as in shorten a carriage. Today it's generally a 2-door pillarless hardtop car with a wheelbase between 100 and 102 inches.