FAQ for
Blow-Up (1966) More at IMDbPro »Blowup (original title)

The car was a Rolls-Royce Silver Cloud III, with a coachbuilt convertible body by Mulliner Park Ward, to the design by Vilhelm Koren. It is informally known as the "Chinese Eye", due to its slanted headlights. It has the same chassis as the Silver Cloud III, but it looked very different due to its coachbuilt bodystyle. About a hundred cars of that bodystyle was built, in coupe and convertible form, between 1962-66. The car used in the film belonged to 60's media personality Jimmy Savile and the car was originally white but was painted black for the use in the film. You can read more about that particular model at this place. Or the Wikipedia article for that car.