- Cast the Expert: Benny the Jet, a legendary kickboxer as well as Cusack's personal trainer, has a role as an assassin (his character is also Basque, which ancestry Benny has as well).
- Fake American: Brit Minnie Driver as Cusack's old love interest, from his hometown in Michigan.
- Incestuous Casting: Played with. Joan Cusack's character seems to be harboring a crush on Martin. (Martin doesn't reciprocate, he's too hung up on Debbie.) The Cusacks have something of a history of this trope.
- Pop-Star Composer: Joe Strummer. Huh.
- Production Posse: This is not the first time John Cusack got his buddy Jeremy Piven and sister Joan Cusack cast in supporting roles.
- Real-Life Relative: In addition to the Cusack siblings in the main cast, their sister Ann plays a drunken woman who accosts Martin and Debi when they're at the restaurant, and their brother Bill also appears at the reunion.
- Throw It In!: One of the reasons for the quirkiness and enduring appeal of the film is that it was built with this. Director George Armitage said that each scene was shot three times: once with the actors saying the lines as written, once with them being given the freedom to play around with them a bit, and once with them being free to say whatever they wanted, as long as they hit the story beats. In nearly every case, he went with the take that had the most improvisation. Minnie Driver in particular is visibly enjoying herself in this movie.
- What Might Have Been: The original script does not have Martin and Debbie reuniting at the end, as foreshadowed by Debbie's line that he doesn't get to have her.
Trivia / Grosse Pointe Blank