Supergirl - Das Mädchen von den Sternen (1971)

A mysterious young woman named Francesca Farnese suddenly appears on a Bavarian highway, dressed only in an orange jumpsuit, and says she wants to go to Washington. Playboy Charly first takes her to Lake Starnberg, where she meets bestselling author Evers. Evers promptly leaves his wife and travels with Francesca to Spain to negotiate a project there with American film producer Polonsky. The mysterious beauty makes a strong impression on everyone she meets. Near the end of the film, she claims to come from the third planet of the star Alpha Centauri and warns of an impending invasion of Earth by the war party on her planet. A short time later, she disappears without a trace. The film does not resolve whether her claim is true.