One Million Dollars(1964)

Original title: La congiuntura

Don Giuliano Niccolini Borges, Roman prince and member of the Pontifical Noble Guard, is very much attracted to Jane, an English girl accompanying him on a pleasure trip to Switzerland. He has plans for hanky-panky along the way, but Jane has her own motives as she's only with him because his car has a special-identification license plate and can go through customs without inspection.