The P538 had a limited European racing career due to rule changes and company finances, but it also spawned Bizzarrini’s first mid-engine road car. Commissioned by a member of the Italian Royal Family, Prince Amedeo, the Duke of Aosta, the car was built in 1968 using the P538 as a base, with a Chevy V8 and a manual gearbox. The resulting one-off, the Duca d’Aosta, is one of the rarest Bizzarrini designs.