Federico Fellini original intended this as his followup to The Nights of Cabiria. Sophia Loren and Gregory Peck were set to star. Only when Loren's illegal marriage to Carlo Ponti made it impossible for her to come to Italy, Fellini left the project and made La Dolce Vita instead...
Giannini and Hawn are on the West coast of Italy, traveling by car towards North, therefore the sea would be on their left, instead it is on the right.