Continuity mistake: In the opening sequence, Felix (Jack Lemmon) goes into the Metropole Cafe. One of the people he passes as he enters is a young woman with a thin face and very distinctive nose and eyes. He goes in, has a drink, hurts his neck, and leaves. As he is leaving, the camera pans the band and go-go dancers. One of the dancers is the young woman who had just left as he was entering.
Continuity mistake: When Thorndyke and Havershaw are working in the garage towards the end of the movie, you can see Thorndyke brings down his oil pistol from the ramp when Havershaw reminds him about the wager he made with Mr Wu, but in the next shot Thorndyke is holding his oil pistol near the ramp again.