Doris Day proved what a trouper she truly was when James Garner accidentally cracked two of her ribs (during the massage scene, when he pulls her off of Polly Bergen). Garner wasn't even aware that Day was injured until the next day, when he felt the bandage while putting his arms around her.
Something's Got to Give was the last movie Marilyn Monroe worked on. It co-starred Dean Martin and Cyd Charisse. It was supposed to begin filming on April 23, 1962, but the schedule was reorganized due to Monroe suffering a sinus infection. Production shot around her scenes using the rest of the cast. Soon enough, the shooting fell 10 days behind schedule. Monroe's last day on the set fell on her birthday, June 1, 1962. When Monroe called in sick again the following Monday, June 4, she was fired a few days later on June 8. Dean Martin refused to continue filming without Monroe, and Marilyn was quietly rehired, but, due to her death, the movie was left unfinished. The following year, it was recast (and tailored for Ms. Day) with James Garner, Doris Day and Polly Bergen, retitled Move Over Darling and released in December 1963.
The producers scheduled the scene with Doris Day riding through a car wash for the last day of shooting because they were concerned 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.
When Bianca is helping Nicholas out of the car and into the house (Nicholas pretending to have hurt his back), the jacket Bianca is wearing is the same pattern/material as one of Marilyn Monroe's dresses from Something's Got to Give (1962) - specifically, Marilyn's dress when she first comes home and sees her children in the pool (on which this film's script is based).
This film is loosely based on Alfred, Lord Tennyson's famous poem "Enoch Arden." In the poem, a husband is shipwrecked and presumed dead, only to return home to find his wife involved with a man he used to know. In this film the roles of husband and wife are reversed. The poem also served as the source material for My Favorite Wife (1940), the film of which this is a remake, as well as another box office hit of 1940, Too Many Husbands (1940).
The hotel used as the Monterey hotel, where Nick Arden goes with Bianca (and to which he'd first gone when he married Ellen) is actually the Beverly Hills Hotel. As such, it's not on the ocean's edge (Beverly Hills is several miles inland). The long-shot of the hotel with the ocean (and the incorrectly 'setting sun' - see 'goofs' about that) in the background are a matte shot.
When Ellen Arden (Doris Day) drives up to her home, the incidental music playing is'Something's Got To Give,' which was the film's original title, when it starred Marilyn Monroe and Dean Martin and Cyd Charrise, and is played here as a small acknowledgement of this.
The Arden's house - which was originally built for Something's Got To Give - is a (very accurate) recreation of 'Something's' director's home; George Cukor. There were some slight changes between it's use in 'Something,' and here in Move Over, Darling' most notably the pool's perimeter was painted, and also as Ellen (Doris Day) first walks to the pool area, the house (on the left side) has a (far back) door, and a 2nd door, and some shrubs. When it was in 'Something,' the shrubs were actually an open-sided space, with part of the house's upper-stories overhanging it.
As most people who see this film know, this film's a re-worked version of what would've been Marilyn Monroe's Something's Got to Give (1962), and there's many bits of trivia surrounding this production. Elliot Reid, who plays Dr. Schlick in this version, had co-started with Marilyn in Gentlemen Prefer Blondes (1953), as Ernie Malone, who's sent by Lorelei (Marilyn) Lee's boyfriend (Gus Edmond)'s father, to spy on her, so he can prevent his son from her.