In the scene where Dave the Dude is asked to be godfather to Ann-Margret's first child, Hope Lange's black dress is unzipped in the back when she is on her way up to the door, and then zipped at the end of same scene.
When Dave demands $100,00 from Darcey, he is shaking his fist while holding an apple. The camera cuts to another angle, and Dave is shaking an empty fist.
After the fight at the dock Dave the Dude and Joy Boy are in the apartment waiting for Darcy to call. Dave is laying on the couch throwing darts with his feet up. In the long shot a newspaper is resting flat under his feet but when shown closer up the newspaper is re-positioned laying against the back of the couch so the headline (FBI HINTS DARCY IS IN NY) can be read.
In the early part of the film, Queenie is talking to Dave about her dream house in "Silver Springs, MD". The city is actually called Silver Spring.
The Dude's apartment is of 1950-60s design with furniture of that era.
1950s-era taxis and other vehicles appear in rear projection footage of city streets seen in the rear window of Dave's limousine.
During the police escort to the boat in the last few minutes of the movie, a 1949 Cadillac can be seen in the rear window of the car the governor is riding in on the right side of his head. The movie is set in 1930's
The film is set in 1931, with a reference being made to 'Mr Moto'. However, the first Mr Moto book was published in 1935 and the first film featuring 'Mr Moto' made in 1937
Hope "Queenie" Lange is wearing 1950s stiletto heels.
(at around 2h) The orchestra perform their piece for the reception and all the string players are playing "arco" (bowed). However the bass line is distinctly heard as "pizzicato" (plucked). Both the cello and the double bass players should be seen using their fingers to produce the notes and not their bows.