Automobile designs that were ahead of their time when exhibited during the early 1930s included "teardrop streamlining at the rear, similar to what would become known as 'fastback' 25 years later. 'Fastback' was first recognized as a definition by Merriam-Webster in 1954, many years before the term 'hatchback' was popularized and entered the dictionary in 1970. Opinions vary as to whether the terms are mutually exclusive.
A contributor to an automotive-interest website singles out the unusual Stout Scarab from the early 1930s as "[p]ossibly the epitome of the early fastback definition". The Packard 1106 Twelve Aero Sport Coupe, introduced in 1933, is cited elsewhere as a fastback that foreshadowed trends which continued into the 1940s.
Numerous fastbacks were also made in America, where the style was previously called "torpedo back". They included Cadillac's Series 61 and 62 Club Coupes as well as various models from General Motors, Ford, and Chrysler.
The trend towards a more steeply raked rear window on traditional "three-box" sedans blurs the distinction between fastback and notchback designs. The current Lexus LS460 exemplifies the trend. However, the roof of a true fastback design slopes down continuously to the rear, most often to the base of the trunk at the rear bumper. There is no distinct change of angle to a rear deck, whereas most four-door cars with steeply raked rear windows have less angled trunk lids; also high tails to maximize cargo space.
In 2008, the fastback design appeared on a concept car that almost defies categorization, the Chrysler ecoVoyager, that "Jack Telnack, former design chief for the Ford Motor Company, declared, 'It’s a fastback van.'" New types of crossover vehicles and different body proportions made possible by technological advances and new powerplants, are changing the shape of automobiles. Traditional nomenclature describing distinct vehicle bodies, such as the three-box sedan (engine compartment, passenger cabin and trunk) will vanish.