Supercar VAZ 21099i

However, the proper application of the term is subjective and disputed, especially among enthusiasts. So-called vehicles are typically out of the ordinary and are marketed by automakers to be perceived by the public as unusual. The supercar can take many forms including limited production specials from an "elite" automaker, standard looking cars made by mainstream companies that hide massive power and performance, as well as models that appeal to "hardcore enthusiasts" from "manufacturers on the fringe of the car industry".
History of the term "supercar"
An advertisement for the Ensign Six, a 6.7 L (410 cu in) high-performance car similar to the Bentley Speed Six, appeared in The Times for 11 November 1920 with the phrase "If you are interested in a supercar, you cannot afford to ignore the claims of the Ensign 6." The Oxford English Dictionary also cites the use of the word in an advertisement for an unnamed car in The Motor dated 3 November 1920, "The Supreme development of the British super-car." and defines the phrase as suggesting "a car superior to all others". A book published by the Research Institute of America in 1944, that previewed the economic and industrial changes to occur after World War II, used the term "supercar" (author's emphasis) to describe future automobiles incorporating advances in design and technology such as flat floorpans and automatic transmissions.