Greg keeps trying to explain Freud to Diamond, repeating "Id, Id, Id" to which Diamond replies "Idiots!" - this parallels a line from The Good, The Bad, And The Ugly where a characer is trying to read a note, repeating Id, to which Eastwood looks at it and says "Idiots." The pacing is almost identical.
Chapter 8 in the film is titled "The Wrinkles Connection" and features the movie's car chase. Also when Kroller and Tibbs go undercover, their names are Russo and Doyle.
Much of the storyline with the mobsters trapped in the cabin being chased by zombies parallels Evil Dead & Evil Dead 2. Raimi's trademark POV shots are used distinctly in this segment as well.