It's a 1968 Fiat Siata Spring, built by Siata and based on the Fiat 850. The Wikipedia article about Siata says about the Siata Spring:
'In 1968, after a detailed market research among Italian youth, Siata launched the Siata Spring, asports car based on parts from Fiat 850, with front end styled by Enrico Fumia in 1966. The Siata Spring was produced until 1970, when Siata went bankrupt, but the assembly line was purchased by a newly formed company called ORSA (Officina Realizzazioni Sarde Automobili), which moved it to an assembly plant near Cagliari, where it resumed the production of the Spring based on the SEAT 850 Special, thus increasing the engine displacement to 903cc with 47BHP, disc brakes on the front wheels and a maximum speed of 125 Kph. Because of the 1973 oil crisis sales of sports cars in Italy went down, forcing ORSA to end the production of the Spring in 1975.'