Saab

In the 1950s, Rolf Mellde - a Saab engine developer and race enthusiast - designed a two-seat roadster prototype in a barn in Åsaka, near Trollhättan, the site of the main Saab manufacturing facility. The Sonett was introduced in March 1956 at Stockholm's Bilsalong (motor show). Featuring a three-cylinder 748 cc engine, an aluminium chassis and fibreglass body, the Sonett was an advanced low-weight racer based on aircraft design concepts. Only six vehicles were made between 1955 and early 1957.

After a nine year hiatus, the Sonett II was introduced in 1966. It had a three-cylinder 841 cc engine which was replaced by the four-cylinder 1,498 cc Ford Taunus V4 engine in 1967. The model was consequently named Sonett V4. Production increased to 900 units in 1968, most of which meant for export to the USA. 

The 1970 redesign of the Sonett V4, named the Sonett III, was initially undertaken by Sergio Coggiola, but Gunnar A. Sjögren altered it to fit the existing Sonett II chassis without expensive manufacturing-line changes. In 1972 the engine was enlarged to 1,698 cc but disappointing sales, especially during the 1973 oil crisis, led Saab to end production in 1974. A total of 8,368 units were manufactured between 1970 and 1974.