The producers scheduled the scene with Doris Day riding through a car wash for the last day of shooting because they were concerned that the detergents used in the car wash might affect the star's complexion. When the scene went off without a hitch, they admitted their ploy to Day, then used the story in promotional materials for the film.
Doris Day wrote in her 1975 autobiography that because of her cracked ribs, she was so mummified with tape and bandages under her costumes that it was difficult to breathe and painful to laugh.
When Grace faints, Ellen takes some roses out of a vase to sprinkle water on her. When it doesn't work, she sets the flowers down on a chair. Later she goes to make a phone call, and sits in the chair, and the flowers appear on the table instead.
When Ellen is in the hotel room with Nick, in mid-scene, her wig changes. Obviously, the scene was shot more than once with different hair and then spliced together.
Bianca Steele: Oh, you are such a comfort, doctor. You know, I truly believe the most vital relationship a woman can establish is not between man and wife. It's the relationship between a woman and her analyst. Don't you agree, Dr. Schlick?