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.
How did Rose get on the flight to Tucson? Assuming she was able to go back to the strip club and retrieve the plane ticket David bought for her, she would have had to buy a new one with her real name on it.
Rose O'Reilly: [Scottie P. is trying to make out with Casey, who is resisting]
Hey! Get your hands off of her! Come here, Casey. Now, you put your hands on her one more time, I swear I'm gonna rip that fucking tattoo right off of your chest.
What are the differences between the Theatrical Version and the Extended Cut?
In the US, both the DVD and Blu-ray release contain the Theatrical Version as well as an Extended Cut. Since Warner Bros. don't release Unrated Versions anymore, the Extended Cut got an R by the MPAA as well. Contentwise, the 8 additional minutes offer more sleazyness so the missing "Unrated" term shouldn't be overrated. Around 30 differences can be found and a detailed comparison between both versions with pictures is available here.