When Quaid/Hauser is fighting the synthetic on top of the six-way elevator car and the synthetic loses an arm, this is a nod to the original film where Michael Ironside's character suffered in a similar way.
Most of the futuristic-looking firearms are actually contemporary weapons with little to no modification. The silver handgun carried by Lori Quaid and by various police in its blued form is a Chiappa Rhino .357-caliber revolver with a laser sight fixed under the muzzle; the police carry TDI Vector .45-caliber submachine guns; and the resistance fighters mostly carry Heckler & Koch firearms, including G36C assault rifles and UMP and MP5 submachine guns.
The announcer in the holographic advertisement for Rekall says, "We can remember it for you." The film is loosely based on a short story by Philip K. Dick called, "We Can Remember It For You Wholesale."
The bank that Douglas goes to is called the First Bank of New Asia. New Asia was the original title for "The Colony", but was changed to "The Colony" in order for people to get the impression that it was more of a melting pot.
When Quaid retrieves his safe-deposit box, next to the United Federation of Britain 50 currency unit note with Barck Obama is a 1000 currency unit note with a picture of Loren Wiseman, father of director Len Wiseman.
There is a welcoming sign at the station in the Colony, at both sides of the Colony's logotype, that is written in Czech and Bulgarian languages: both Slavic languages using Latin and Cyrillic alphabet respectively. Great Britain, the Czech Republic and Bulgaria are European Union member states. It seems at the end of the XXI century Czechs and Bulgarians live in the Colony, modern day Australia, while at the beginning of this century they are not among the 40 largest Diasporas of immigrants in Australia.
The trivia items below may give away important plot points.
When Quaid attempts to pass through the security check at the entrance to UFB, he is wearing a holographic necklace that produces the image of an Asian man's face. Moments before, a woman with a chubby face, wearing a yellow coat, can be seen. The woman is a red herring as she very much resembles the prosthetic/mechanical "mask" worn by Quaid in the correlating scene of Total Recall (1990). She even gives the same answer to the security clerk ("Two weeks").
Ethan Hawke was announced as a part of the cast in an undisclosed role but his role ended up being cut. He played Cole Hauser, Colin Farrell's character in a flashback, a scene which has been restored in the director's cut.
Quaid's real name "Hauser" was the name of a 19th century foundling, Kaspar Hauser, who seemed to have spent his entire life in a dark room with no connection to the outside world. He appeared as a teenager and was thought to be a heir of noble descent. This theory was disproved later. He died of a knife wound and told that he was attacked (like Quaid) but there is no positive proof that incident really happened.