Bubble car is a subjective term used for some small, economical microcars, usually produced in the 1950s and 1960s.
The Messerschmitt KR175 and KR200, and the FMR Tg500, had aircraft-style bubble canopies, giving rise to the term bubble car to refer to all these post-war microcars. Isettas and others also had a bubble-like appearance.
Bubble cars became popular in Europe at that time as a demand for cheap personal motorised transport emerged and fuel prices were high due in part to the 1956 Suez Crisis. Most of them were three-wheelers, which in many places qualified them for inexpensive taxes and licensing as motorcycles.
Most bubble cars were manufactured in Germany, including by the former German military aircraft manufacturers, Messerschmitt and Heinkel. Automobile and motorcycle manufacturer BMW manufactured the Italian Iso Rivolta Isetta under licence, using an engine from one of their own motorcycles. France also produced large numbers of similar tiny vehicles called voiturettes, but unlike the German makes, these were rarely sold abroad.
The United Kingdom had licence-built right-hand drive versions of the Heinkel Kabine and the Isetta. The British version of the Isetta was built with only one rear wheel instead of the narrow-tracked pair of wheels in the normal Isetta design in order to take advantage of the three-wheel vehicle laws in the United Kingdom. There were also indigenous British three-wheeled microcars, including the Trident from the Peel Engineering Company on the Isle of Man.