The Monteverdi Hai 450 SS is a mid-engined prototype sports car built by Monteverdi to complement the company's High Speed line. It was intended to be a direct competitor to high end sports cars from Lamborghini, Ferrari and Maserati.
A magenta Hai 450 SS prototype debuted at the 1970 Geneva Auto Show. It had a V8 from Chrysler positioned behind the two seats. Its name combined the German word for "shark" (Hai) and the rated output of the engine.
A second car was built with a longer wheelbase and minor detail changes like door handles and red bodywork. This car was named the Hai 450 GTS to mark the changes.
Monteverdi initially planned to produce 49 copies, but production was halted after the two prototypes. Only one car was actually sold, although in a 1974 interview Peter Monteverdi claimed to have delivered eleven of the cars. In the 1990s, Monteverdi used spare parts to build two additional replicas, which now reside in the Swiss National Transport Museum in Luzern.
Paul Frère tested the 450 SS, reaching in 6.9 seconds and a top speed of . The 450 GTS, tested by Autozeitung, reached in 5.5 seconds and a top speed of . Curb weight of the 450 SS was as tested by Automobil-Revue in 1970, considerably higher than the factory numbers.
Like Monteverdi's front-engined cars, the Hai made extensive use of Chrysler parts. It has the same de Dion rear axle as the 375 High Speed, and may be the only mid-engined car ever to have used recirculating ball steering.
The body design is usually attributed to Trevor Fiore, of Carrozzeria Fissore, although some sources credit Pietro Frua.