Write What You Know: While he was staying in Hollywood, Evelyn Waugh had become fascinated by the Forest Lawn memorial park, visiting several times a week and becoming friendly with the staff, so it was easy for him to write the amused reactions of an Englishman like Dennis to a themed cemetery like that since he was just transferring his own experiences.
Dawson Casting: Yes, that's a young Paul Williams as Gunther Fry, but he wasn't that young. He was around 24 at the time. But his famously diminutive height and his decision to pitch his voice way up for the role makes him convincing as an adolescent.
Disowned Adaptation: Evelyn Waugh hated the script and tried to get his name removed from the credits. He died shortly after the English premiere and apparently never saw the finished product.
Fake Brit: Massachusetts native Robert Morse as Dennis Barlow.
Irony as She Is Cast: Robert Easton, who was a respected dialect coach as well as a prolific character actor, as an actor who's having trouble learning to do an English accent. In fact, he was working on the film coaching Robert Morse on his accent.
Billy Wilder tried to get the film rights to the novel shortly after it was published but got turned down. Instead he made Sunset Boulevard, which borrowed the Horrible Hollywood setting and a few little points from the story (Joe Gillis as a bit of an Expy of Dennis Barlow, the decaying mansion with the empty swimming pool, pets dying).
Several other filmmakers were attached to a possible adaptation of the novel in the years before the film was made, including Luis Buñuel and Elaine May.
