
Other mistake: Jon's Volvo back license plate number in the first half of the movie is T03-851. When he and Dr Liz are looking for Odie, his front license plate number is I35-749. As they are pulling up to the train station, the Volvo in front of them also has the plate I35-749.
Answer: The song is called "Holla", by the Baha Men (of "Who let the dogs out" fame).