Clint Eastwood was given the choice of taking $25,000 in cash or $20,000 and a new Ferrari by Producer Dino De Laurentiis to play a small part in this movie. He chose the money and the Ferrari. He got along well with Silvana Mangano and Director Vittorio De Sica.
Reputedly, the reason Clint Eastwood took the Ferrari as part of his payment was so his agent wouldn't be able to get ten percent of the car.
The Clint Eastwood incident was humorously referenced in Federico Fellini's segment of the anthology Spirits of the Dead (1968). Terence Stamp played an actor arriving in Rome to do a movie, and as they leave the airport to go into the city, he suddenly sits up and asks where his Ferrari is. He was promised a Ferrari.
Clint Eastwood filmed his part after completing the final series of Rawhide (1959 -1965) and just before starting The Good, the Bad and the Ugly (1966).