Actor Allusion: Jeff Goldblum often mentions a dislike of snakes in his roles. Here though, after Diana she can't stand them, he says "Right now a snake would be reassuring."
When he drives away in Jack's car, he says " Banzai."
Hey, It's That Guy!: if it's possible to be Trope Overdosed on a single trope, it's this film and this trope:
Herb (Ed's work friend) is played by Dan Aykroyd
Ed and Herb's boss is played by David Cronenberg
Colin Morris (the psychotic British hitman) is played by David Bowie
the doorman of the Beverly Hills Wiltshire is played by Paul Bartel
the nameless man who is pushed off a public phone is played by Jim Henson
John Landis likes to cast Frank Oz in his movies, but Oz was unavailable, so he brought in Henson. During the airport climax you can hear the PA system paging a "Frank Oskovitz", Oz's real name.
Monsieur Melville (French gangster and employer of Morris) is played by Roger Vadim
one of the four SAVAK agents pursuing Ed and Diana is played by the director, John Landis (he's the one with glasses, who never speaks)
The aforementioned Brother Charlie is played by D-Day.
Landis throws a lot of bit-part bones to his behind-the-camera buds: look for Lawrence Kasdan, Jonathan Demme, Paul Mazursky and even Amy Heckerling.
Carl Perkins plays Mr. Williams — rock music historians will certainly enjoy the knife fight to the death between Mr. Blue Suede Shoes and Ziggy Stardust.