Mauvais Sang (1986)

This French film is also known as "The Night is Young" and "Bad Blood" (in the US) and is a flashy riff on the gangster film.  The director Leos Carax has a definite eye for the cinematic and focuses on that rather than on a believable story.  The two main stars are Juliette Binoche and Denis Lavant who also appear together (as different characters) in the director's "Les Amants du Pont Neuf".  The convoluted tale is about two old crooks -- one of whom is played by Michel Piccoli, a strange sort of role for him -- who are being strongarmed by an American gang to steal a serum for an AIDS-like disease (which is sexually transmitted only when the lovers are not in love!)  They recruit Lavant who is the son of a murdered colleague since he is light-fingered (he is also something of a magician) and he falls for Binoche who is Piccoli's moll despite the age difference; he leaves his previous girlfriend, the motorcycle-riding very young Julie Delpy.  I think the best way of viewing this movie is to forget about the story and try to focus on the poetry of the cinematography; otherwise your response might be uncharitable.