In the 2003 DVD commentary, Alan Arkin relates that Marlon Brando once told him he had seen 'The In-Laws' 20 times, and even imitated Arkin's delivery of certain lines from the film. Writer Andrew Bergman concurs that Brando's appreciation of his script was integral to getting Brando to star in The Freshman (1990).
When Vince is getting directions to meet the general, the streets include "United Fruit Boulevard," a reference to the U.S. Company that historically dominated much of Central America and gave rise to the expression "a banana republic."
Decades before Peter Falk played the part of a CIA agent, and well before he decided to become an actor, Falk applied for a job at the CIA (during the McCarthy era). Falk managed to get an interview with the CIA, but his interviewer told him that one of the schools he went to, the New School for Social Research, had a "pinkish" reputation, and that because Falk once was a member of the "communist-dominated" Marine Cooks and Stewards Union, he not only couldn't work for the CIA, but wouldn't find work anywhere in Washington.