Jean Peters got the role of Polly Cutler after Anne Baxter withdrew. After her withdrawal, the film was reworked to highlight Marilyn Monroe.
The model car that George Loomis (Joseph Cotten) is making in the film is a 1907 Maxwell. This is a nod to co-star Don Wilson, who plays the boisterous businessman J.J. Kettering. Wilson was the longtime announcer on Jack Benny's radio show. On the show, Jack Benny's car was a 1907 Maxwell. It's sputtering, coughing, wheezing engine (a vocal sound effect provided by Mel Blanc) was a well-known recurring gag on the show.
SPOILER: This is the only Marilyn Monroe movie in which her character dies.