Renzo Rivolta's Isothermos company had begun life pre-war making refrigerators, turning to the manufacture of scooters, under the Iso name, after the war and thence to the highly successful Isetta 'bubble car'.

Introduced in 1953, the egg-shaped Isetta was like nothing seen before, boasting a hinged front for entry, the steering column and instruments swinging out with the door to facilitate easy access to the bench seat.

Power was provided by a 236cc two-stroke engine, which drove the closely-spaced twin rear wheels via a four-speed gearbox.

In the 1954 Mille Miglia, Isettas claimed the first three places in the economy classification, the winner averaging over 70km/h (43mph).

Despite its virtues the Isetta was not well received at home, where small cars like the FIAT 500 were preferred, and sales were disappointing.

Production in Italy ceased after some 1,000-or-so had been made, though the design continued to be built under license in several other countries.

BMW saw its poten...