Whenever he is shown walking, Max 404 keeps his arms bent at a level that imitates C-3PO in Star Wars: Episode IV - A New Hope (1977).
The pneumatic air-hiss of the doors opening and closing was created by the sound effects editor, who aimed a can of compressed air into a five-gallon plastic water jug. He would pull the tube of the air nozzle out of the jug while pressing the button, which produced the doors' sound.
After auditioning many actresses for the part of Maggie, director Aaron Lipstadt met Brie Howard (aka Brie Howard-Darling) at a party. At the time she was a drummer in an all-girl band, but he liked her looks and asked her to try out for the role.
Don Opper based his performance of Max's peculiar, C-3PO-like walk on Charles Chaplin and Buster Keaton.