For the scene where Natalie is distracting the surfer at the beach and Alex and Dylan are underneath his GTO collecting clues, the car had to be put on jacks because the actresses couldn't fit underneath it.
Drew Barrymore really wanted Bon Jovi's "Living on a Prayer" in a flashback scene. However, the rights to the song were too expensive, so Barrymore called Jon Bon Jovi told him how much she loved the song and how important it was to her that it be in the scene, and Bon Jovi found a loophole to enable them to use the song.
Bill Murray did not want to reprise his role as Bosley because he refused to work with McG again. Murray also had problems with Lucy Liu on the first Charlie's Angels (2000) film, but publicly insisted that Liu was not the reason for his departure.
All of the Irish characters (including the henchmen) are either Scottish, English, or American. None of them actually come from Ireland. This was referenced in deleted scene where Bernie Mac complains that the Irish accent he is putting on sounds just as real as theirs.
When O'Grady gets released from prison, the picture on his wall of Dylan is a still of Drew Barrymore from the Charlie's Angels (2000) back story montage when she was smoking in the bathroom with a cast on her arm.
In the weeks prior to the film's release, a series of short animated adventures featuring the voice of John Forsythe as Charlie were produced and distributed over the Internet. Charlie's Angels: Animated Adventures (2003) expand upon events shown at the start of the film.
In the M.C. Hammer dance scene and the hot dog seller scene, Dylan has the word Kodachrome written in black pen on her left forearm. Kodachrome is the title of a 1973 song written by Paul Simon. This movie was shot on Kodak film stock.
One scene shows the Angels masquerading as welders while the song "What A Feeling" from the movie Flashdance (1983) plays on the soundtrack; Drew Barrymore previously co-starred in the movie Wishful Thinking (1997) with Jennifer Beals, who had starred as a welder/dancer in Flashdance (1983).
The trivia items below may give away important plot points.
Bruce Willis' Senator character is shot in the head by Madison, Demi Moore's character, or perhaps someone working for her, as it is never made clear who pulled the trigger. In real-life, the two had just recently gotten divorced.
When Madison and Natalie are on the beach talking, Madison is wearing a black bikini and Natalie is wearing a white bikini which foreshadows that Madison is the 'bad guy' and has gone dark and represents that she is no longer an Angel, while Natalie is loyal to Charlie and is still considered to be an Angel that is innocent; hence the white.