The flashback at the start featuring footage from The Karate Kid Part II (1986) features a snippet of never before seen footage when Daniel replies "I know" to Miyagi. This part of the scene was not in the feature film version.
Amanda LaRusso calls John Kreese "Rambo". Martin Kove, who plays John Kreese, appeared in Rambo: First Blood Part II (1985) as Ericson.
The scene where Johnny lies about Miguel being a "Make-A-Wish" child to get into a Dee Snider concert has a real-life parallel to a 20/20 news story relating to allegations of misuse of the Make-A-Wish foundation, including one incident that claimed two teenagers manipulated a sick prepubescent child to enable them to attend a Twisted Sister concert, which had Snider as its vocalist, with her under the same kind of false pretense.
When Daniel enters Chozen's dojo, the magical shrine from the animated series The Karate Kid (1989) can be seen displayed on a shelf.
In the jail-time visit scene between Robbie Lawrence and John Kreese, Kreese talks about Johnny Lawrence in his first tournament losing to Vidal. Vidal is actually a reference to real life black belt karate expert Darryl Vidal, who starred as a self-named character (simply as 'Vidal') in the original movie. He was the losing semi-finalist to Johnny Lawrence in the All Valley 1984 tournament (his name is up on the competition progress boards). Darryl Vidal was also Pat Morita's stunt double, doing the crane kick on the beach scene in the original film.