Just after Frank's house explodes, the black cop says, "Two days to retirement" as a nod to Danny Glover's character in Lethal Weapon. At that point, you can hear a soundtrack excerpt from the Lethal Weapon theme in the background.
The explosion of Jack Slater's ex-wife's house was used from The Last Boy Scout, also written by Shane Black.
When Danny is arguing with Slater over checking to see if Benedict is dead after the two play chicken, he makes a reference to a villain in Die Hard (also directed by John McTiernan) who comes back at the end of the movie after being presumed dead. Shortly after, you can hear a soundtrack excerpt from the Die Hard theme in the background
"Jack Slater" when trying to pose as Arnold Schwarzenegger in the "real world" keeps getting the name wrong, and calling himself "Arnold Braunschweigger." The first part of Arnold's real name, "Schwarz," means "black" in German, while the first part of his wrong name, "Braun," means "brown" in German. Also, "Braunschweiger" means "Brunswicker" (man from Brunswick) in German.
The film makes several oblique references to the Governor of Los Angeles. These are eerily prescient statements to make with Arnold Schwarzenegger later becoming the Governor of California.
When Jack and Danny are in the video store we see the boxes for Die Hard, The Hunt for Red October, and Medicine Man, which were all directed by John McTiernan.
The scenes that's playing on the TV monitor in the Blockbuster store, are from the movie Thunderheart.
The words "A Franco Columbu film" appear on the screen at the beginning of Jack Slater IV. Columbu is a bodybuilder friend of star Arnold Schwarzenegger's, who has appeared in the following films with him: Pumping Iron, Conan the Barbarian, The Terminator, The Running Man and Beretta's Island.
When Danny and Slater arrive at LAPD headquarters, Sharon Stone and Robert Patrick appear outside the front door as Catherine Tramell (from Basic Instinct) and the T-1000 (from Terminator 2: Judgment Day), respectively.
In the Blockbuster store, there is a cardboard cutout for Terminator 2: Judgment Day. The actor shown instead of Arnold Schwarzenegger is Sylvester Stallone.