The Monteverdi Hai 450 SS was a mid-engined prototype, an attempt to create a full sports car complementing the company's High Speed line.

It was intended to be a direct competitor to the top of the list super sports cars of Lamborghini, Ferrari and Maserati.

[3][4] In the 1990s, two additional replicas from spare parts were made by Monteverdi, those now reside in the Swiss National Transport Museum in Luzern.

[5] Curb weight of the 450 SS was 1,756 kg (3,871 lb) as tested by Automobil-Revue in 1970, considerably higher than the factory numbers.

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 a recirculating ball steering setup.