The song that Kincaid and the nuns are singing together in the van (much to Bryce's annoyance) is a 19th-century Italian traditional drinking song named "Bevilo Tutto", which encourages everyone to 'drink it all up'.
Gary Oldman learned to speak fluent Russian for his role as the villain Dukhovich. Despite no prior knowledge of Russian, Oldman was required to speak it expertly in the film. "I probably could have learned 'Hamlet' measure for measure in the time that I've spent on my lines," he laughed. Nevertheless, working with a Russian coach daily, Oldman did just that.
Perhaps the biggest challenge for actress Salma Hayek was her character Sonia's epic bar fight, which convinces Kincaid (Samuel L. Jackson) she's the one for him. Selma said she "was sore for a week after we shot that," she admitted. "But I'm so happy that at 49, I am still kicking ass and able to do all my stunts."
The movie poster showing Ryan Reynolds carrying Samuel L. Jackson is a spoof of the poster for Bodyguard (1992) where Kevin Costner is carrying Whitney Houston. Even the taglines are the same (albeit with pronoun changes).
The song "Nobody Gets Out Alive" sung by Darius Kincaid (Samuel L. Jackson) during the car ride was written by Jackson himself. He performs the full song again during the end credits.