Isetta

The Isetta is an Italian-designed microcar built under license in a number of different countries, including Spain, Belgium, France, Brazil, Germany, and the United Kingdom. Because of its egg shape and bubble-like windows, it became known as a bubble car, a name later given to other similar vehicles. In 1955, the BMW Isetta became the world's first mass-production car to achieve a fuel consumption of 3 L/100 km. It was the top-selling single-cylinder car in the world, with 161,728 units sold.