Sergio Scaglietti, who used intuitive genius and a hammer — seldom blueprints or sketches — to sculpture elegant Ferraris that won Grand Prix races in the 1950s and ’60s and now sell for millions of dollars, died on Nov. 20 at his home in Modena, Italy. He was 91.

Luca di Montezemolo, Ferrari’s chairman, announced the death.

Ferraris, with their hair-raising acceleration and sleek lines, bespoke postwar modernity in the manner of the Color Field paintings of Barnett Newman and Mark Rothko or the architecture of Eero Saarinen. Mr. Scaglietti in the 1950s designed the blood-red skin of the 375MM sports car that the film director Roberto Rossellini, the master of neo-realist cinema, gave to his wife, Ingrid Bergman.

In August, Mr. Scaglietti’s 1957 Ferrari 250 Testa Rossa sold for $16.4 million, said to be the most ever paid for an automobile at auction. His 250 GT California Spyder was the vehicle in which the teenage heroes of the 1986 film “Ferris Bueller’s Day Off” cavorted. (The Ferrari in the movie was actually a fake: the producers couldn’t afford a real one.)