Facts about Die Hard!
1. While in early development with a script that was eventually discarded, the movie had been given the subtitle "Tears of the Sun". Bruce Willis told the studio he would commit to a Die Hard 4 if he could use the title for Tears of the Sun (2003).
2. The French title translates as "Die Hard 4.0: Return to Hell".
3. "Yippee Ki Yay Motherfucker" in the movie was voted as the #96 of "The 100 Greatest Movie Lines" by Premiere in 2007.
4. Prints were sent out to UK cinemas under the fake name "New Hampshire" - a reference to the state's "Live Free or Die" motto and the movie's original title - in spite of the title being changed to "Die Hard 4.0" in European territories.
5. This film addresses the apparent continuity error in earlier installments - McClane is afraid of flying in the first two films, but not the third. Here, he explains that he took flying lessons in order to face his fears.
6. Jessica Simpson auditioned unsuccessfully for the role of 'Bruce Willis (I)' 's daughter. She can be seen on the way to the audition and coming out of the audition in _"Newlyweds: Nick & Jessica" Mismatched Threesome (2004)_ .
7. The movie's title, "Live Free or Die Hard", is a reference to New Hampshire's State Motto "Live Free or Die". Consequently, the New Hampshire state film office received several phone calls asking where in the state the movie was filmed.
8. Bruce Willis's stunt double, Larry Rippenkroeger, was seriously injured when he fell 25 feet to the pavement. He suffered broken bones in his face and fractures in both wrists. Production was temporarily shut down. Willis picked up the tab at area hotels for Larry's parents and visited him a number of times at the hospital. Larry also doubles for James Caan in his TV series, Vegas. Caan came and visited Larry in the hospital and joked around for over an hour. Larry told his parents he was glad when Caan left because he hurt so bad laughing at Caan's jokes.
9. Justin Timberlake was in talks to play John McClane's son.
10. The film was edited down to a PG-13 rating for commercial reasons, thus making it the first film in the series not rated R.
11. In the beginning credits when Kevin Smith's name comes on the screen. The "m" in smith disappears and you see "Sith" for a few seconds paying homage to Kevin Smith's love of all things "Star Wars" which also reflects in his character in the movie.
12. When introduced to an agent Johnson, McClane says: "Johnson, again?". A nod to the two agents Johnson that McClane encountered in Die Hard (1988).
13. In the beginning of the film, John McClane and Lucy have an argument that eventually leads to them discussing her use of her mother's last name, Gennero. This was also a discussion in the first Die Hard (1988) film, as seen when John McClane is searching for the location of his wife, Holly, in the Nakatomi building. He does not find her under Holly McClane, but does find her under her maiden name Gennero.
14. The Terminator action figure in Matt's apartment is a nod to executive producer William Wisher Jr. and composer Marco Beltrami. Wisher co-wrote and appeared in The Terminator (1984) and Terminator 2: Judgment Day (1991), and Beltrami composed the score for Terminator 3: Rise of the Machines (2003).
15. When McClane is driving in Jersey and talking to the chief captain of Camden, the guy's name is Wiseman, same name as the director, Len Wiseman.
16. The screen to the far left of all of Warlock's hacking screens has the auction website ebay open with a Boba Fett action figure being watched.
17. In addition to the 'Agent Johnson' reference, several other elements from the first film are revisited as series trademarks. Among them are: crawling on broken glass, use of air-ducts, elevator shafts, and maintenance areas in corporate buildings, a henchman falling down stairs, an inquiry on the e.t.a. of a helicopter, and McClane's "Yippie Ki Yay' catchphrase.
18. When Gabriel is talking to McClane over the phone and pulling up his information on the computer, Bonnie Bedelia makes a cameo appearance in the form of her character Holly McClane's driver's license photo. The photo appears as though it may be either a publicity shot from a prior "Die Hard" film or a still photo (i.e. family portrait) from one of the movies.
19. All the IP-addresses shown in the movie are legal ones. However, they start with either 10, 172.16 or 192.168. Those numbers are reserved for local traffic only.
20. The video game Gears of War for the Xbox 360 is featured twice in the film: on televisions in the first hacker's apartment and in the Warlock's basement.
21. John McLane's sidearm is no longer a Beretta 92FS, a gun which he used in the previous three movies.
22. On the traffic monitoring screens showing the created traffic jam ups, some reused footage (armored card turning) from the The Italian Job (2003) can be seen.
