The book makes reference to the movie "Summer and Smoke", but incorrectly names Paul Newman as the co-star with Geraldine Page in that film, rather than her actual co-star Lawrence Harvey. Lee Remick was also in "Summer and Smoke"
Just before its release, there was a love scene between Michael Sarrazin and Lee Remick that was cut. This scene supposedly included nudity. In the final cut, their affair is only insinuated.
During the Motorcycle race, Hank takes a spill and gets an entire left side caked with wet mud. The rest of the race and picnic, the level of mud on Hank's clothes changes back and forth from muddy to not so muddy.
Hank Stamper: [singing]
Don't ever hit your mother with a shovel. It will leave a dull impression on her mind. Paul Newman said the same line in "Butch Cassidy and the Sundance Kid".
Man:
You know, Hank, I thought all of you dinosaurs were dead.
Hank Stamper: Well, if they want this one, they're gonna have to shoot 'em. Just like King Kong, yuh gotta knock 'em down.