Jason Lee was meant to have a larger role in this film, but his screen time was rewritten shorter than planned due to scheduling conflicts with My Name Is Earl (2005). Most of his scenes were filled in with Zachary Levi's character, Toby Seville.
The Seville home has a house number of "1958". This is the year Ross Bagdasarian created the animated singing anthropomorphic chipmunks.
David Seville is a stage name of Ross Bagdasarian creator of the Chipmunks. He took the name "Seville" from the town in Spain, where he had once done military service.
It was originally scheduled to be premiered on March 19, 2010, but was moved up to a Christmas 2009 release instead.
Ross Bagdasarian named the Chipmunks after executives at Liberty Records, who released Seville's and the Chipmunks' original albums. Alvin was named for company president Alvin Bennett, Simon for company vice-president/record producer Si Waronker, and Theodore for recording engineer Ted Keep.