* CompletelyDifferentTitle: In France, the film is titled ''"[[AmericanTitle American Trip]]"'' (still in English). One of the main reasons is that French people not familiar with Los Angeles (which is 99% of them and then some) understandably have no idea that the title refers to the Greek Theatre. Another is a bizarre TranslationMatchmaking trend of re-titling movies with "Trip" in them that originated with the already CompletelyDifferentTitle of ''Film/TheHangover'', ''"Very Bad Trip"''.
* MissingTrailerScene: Several brief but prominent moments from the trailer never made it to the movie. Examples include someone suggesting "Mexican Jonas Brothers" as an idea at the record company meeting and Aldous driving down a hallway naked in a toy car saying "I'm a motorist!"
* PlayingAgainstType: Played with. While this film is a straight up comedy, Creator/JonahHill was typecast previously as playing loudmouthed jerks like in ''Film/{{Superbad}}'' and comic relief characters in other Creator/JuddApatow films, this role as Aaron Green he plays a pleasant leading man who just wants to keep his job whereas Creator/RussellBrand is typecast as the funnyman literally playing the same character.
* {{Retcon}}: In this film its stated that Aldous and Jackie Q had been together for years, however in the previous movie Aldous was dating Sarah Marshall. This is rectified by saying that he and Jackie had an open relationship even though there was no mention of Sarah being a side girl.
* StarMakingRole: Though he played Aldous Snow before, this role established Russell Brand as a leading man.
* WhatCouldHaveBeen: Creator/BrieLarson auditioned for an unspecified role.
* YouLookFamiliar: Most obviously, Jonah Hill's main character is different than the guy he played in ''Sarah Marshall'', but Carla Gallo (the "Gag Me" girl) here plays Destiny, and Da'Vone Mcdonald, the bartender Dwayne in the first movie, plays Sergio's security guard.
** [[LateToThePunchline Destiny & The "Gag Me" Girl are (probably) the same person.]]
** Dwayne does mention he moved from South Central LA to Oahu in ''Sarah Marshall'', so the security guard (who is based in LA) could be his twin brother or something.
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