The exterior used for Moon's castle is the same exterior used for Lex Luthor's castle in Smallville (2001).
BTR revealed on MTV in NY that they were staying in a haunted hotel while filming the movie. James scared Carlos so bad that he ran from the window to the door in seconds. They also used a Ouija board one night and left the hotel that same night.
In the scene where the van is floating over the MI6 agents, if you look closely at James and Logan after Kendall says "I'll close it slowly this time" and Penny asks "So where's your sound check?", you can see the clips holding James and Logan to the ceiling of the van.
Emma Lahana's character's name is a parody of The Beatles song "Penny Lane."
As of January 4, 2014, Carlos PenaVega (Carlos Garcia) is married to Alexa PenaVega of the Spy Kids franchise in real life.