The Three Amigos and The Wild Bunch connections:
Both take place right before WWI, both have plots regarding Germans and crates of guns, Alfonso Arau is a villian in The Wild Bunch and the villian (El Guapo) in the Three Amigos, and both movies pretty much rule.
from: Trivia for ¡Three Amigos!
# Alfonso Arau, who plays El Guapo, was one of the main villains in The Wild Bunch (1969).
# Alfonso Arau, (El Guapo), also starred in Tres amigos (1970), which translates to Three Amigos.
from: Trivia for The Wild Bunch
# Supposedly, more blank rounds were discharged during the production than live rounds were fired during the Mexican Revolution of 1914 around which the film is loosely based. In total 90,000 rounds were fired, all blanks.
# According to editor Lou Lombardo the original release print contains some 3,643 editorial cuts, more than any other Technicolor film ever processed. Some of these cuts are near subliminal, consisting of three or four frames, making them almost imperceptible to the naked eye.
# At least three names from this film have been used in the television series "Buffy the Vampire Slayer" (1997). In addition to starring a vampire character named Angel, the series also had an episode (2.12 "Bad Eggs") that featured two vampire cowboys named Lyle and Tector Gorch. Also, Luke Perry's character's last name in the movie version of Buffy the Vampire Slayer (1992) is Pike.
# In an interview, Ben Johnson said that the two Mexican women who "frolicked" with him and Warren Oates in the huge wine vats weren't actresses but prostitutes from a nearby brothel, who were hired by Sam Peckinpah so he could tell people that Warner Bros. paid for hookers for his cast.