16. GM Firebird Concept Cars (1955)
Despite the fact that the first Pontiac Firebird was introduced in 1967, the name was already used by General Motors on four very popular concept cars presented in the late `50s. Named GM Firebird I to IV, those were purely show cars with rocket inspired styling, big fins and advanced equipment.
The first Firebird had a jet engine and was basically an airplane on wheels. Later cars were bit more conventional, but still pretty crazy.