Argentine, Spanish, Belgian, French, Brazilian, German, and British manufacturers all get licenses to produce the Isetta microcar, which was designed in Italy. It was dubbed a bubble automobile, a moniker used by other vehicles with an egg shape and windows that resembled bubbles.
The first mass-produced car to reach a fuel consumption of 3 L/100 km (94 mpg‑imp; 78 mpg‑US) was the BMW Isetta in 1955. It sold 161,728 units, making it the best-selling single-cylinder car ever. The original manufacturer was the Italian company Iso SpA; the name Isetta comes from the diminutive form of Iso, which means “little Iso” in Italian.
h/t: vintag.es