Carlos: What? Were they psychos, or...?
Seth Gecko: They look like psychos? Is that what they looked like? They were vampires. Psychos do not explode when sunlight hits 'em. I don't give a fuck how crazy they are!
Throughout the entire film the tattoo on George Clooney's neck moves position and changes shape.
Sex Machine's 'crotch gun' is also used in the film Desperado which also stars Quentin Tarantino and Danny Trejo (the barkeeper).