Siata (the name comes from Societa Italiana Applicazioni Trasformazioni Automobilistiche) was founded by Georgio Ambrosini in Turin in 1926 to manufacture tuning accessories for Italian (mainly Fiat) cars. Their cylinder heads with overhead valves (for the 500A) were particularly successful, and they also used superchargers for some applications. A few prototypes were built based on the Topolino including some examples of the 500 Gran Sport (1937) which was a spider with a rocket-like body and a 636cc engine. One of these, with a body by Zagato and driven by Piero Dusio (later to found Cisitalia won its class in the 1936 Mille Miglia. The Monza (coupe) and Pescara (spider) (both 1939) which were capable of 135km/h and 125km/h respectively. In 1939 a small number of cars called the Amica were built. Designed by Bertone and with bodies constructed by Motto, these were available as a Cabriolet or Coupe.
The war saw Siata turn to the production of equipment for the military before the site was totally destroyed by bombing in 1943. Following the war Siata launched an auxiliary engine for bicycles which was an immediate success and at the same time changed the meaning of Siata to Societa Italiana Auto Trasformazioni Accessori. and afterwards production again concentrated on tuning accessories.
In 1949 Siata released the new Amica, followed by the Daina and other road cars. Competition cars were also built, based on both Fiats and their own road cars as well as through co-operation with Abarth. In 1961 the company became Siata Auto SpA. Through the sixties and seventies Siata produced cars based on Fiats. Production stopped in 1970 and they finally succumbed to growing financial problems in 1974 when ORSA purchased the name and all manufacturing rights.
There is a lot online about the history.
Another pic of the roadster...
