Will Poulter (Kenny) stayed up late while listening to "Waterfalls", by TLC, to have his character rap along in a scene involving the song. Poulter personally chose the song because he considers himself a hip-hop fan.
The cast played a prank on Jennifer Aniston by playing the Friends (1994) theme song ("I'll Be There For You" by The Rembrandts) instead of TLC's "Waterfalls" during a take. This was the last clip used in the bloopers.
When David is in the strip joint trying to convince Rose to go with him to Mexico, he mentions that it would be "like Pretty Woman." Emma Roberts who plays Casey in this movie is the niece of Pretty Woman (1990) star Julia Roberts.
The coffeehouse scene at the beginning is actually Port City Java on Market Street in Wilmington, NC. The coffee cup seen being held by a character is an actual Port City Java cup with the logo turned to the side.
The front license plate of the Volkswagen Bus, the driver of which gets searched because of a joint, is a German license plate of the city of Wolfsburg, the headquarters of Volkswagen. It also has the numbers 1976, which might indicate the birth year of the owner.
The trivia items below may give away important plot points.
In the scene where the main characters are revealing their real names to one another, David asks if Rose's real name (Sarah) is spelled with an 'h'. This seems to be a direct reference to the same query which was made to 'Elizabeth Shue''s character in Leaving Las Vegas (1995) by Nicolas Cage's character. (Shue's response was that her name is spelled with an 'e': "Sera".)
When David (Jason Sudeikis) is in Brad's (Ed Helms) office in the beginning of the movie, David mentions seeing Dexter. Later in the movie, David meets One-Eye (Matthew Willig). Willig played Little Chino on the second season of Dexter.