Will Forte owned the Mazda Miata that MacGruber drives in the film. Forte revealed that he sold it for $50,000 for charity and he personally delivered it to the buyer in Texas. The man who purchased it then taught his son how to drive stick shift in the Mazda. Forte also brought a MacGruber style costume for the driver to wear.
Val Kilmer and Will Forte almost ended up being on CBS' hit series The Amazing Race (2001) because of this film, where they became good friends. Kilmer later stayed at Forte's house for a few months while searching for a new L.A.-based home for himself, and Forte (a huge fan of TAR) introduced Kilmer to the show. They were about to apply as a team when their other work commitments led to the idea being dropped.
Will Forte said on Bill Burr's podcast that he was paid $12,000 for this film.
When one of the Ecuadorian kids steals the necklace from MacGruber, he says "Chupamelo, MacGruber", in Spanish it means "Suck it, MacGruber".
Jorma Taccone, the film's director, plays a drinking game on the DVDs commentary track where he takes a drink of beer every time MacGruber's name or any variation of it is used in a line of dialogue. He drank four beers.