Synopsis by Erin Demers
When Dave (Jason Lee) introduces Alvin, Simon, and Theodore to his new girlfriend Samantha (Kimberly Williams-Paisley) and her troublemaking son Miles (Josh Green), the chipmunks begin to panic at the thought of Dave proposing to her while on a trip to Miami. Fearing that they will be sent back to the forest if the relationship becomes too serious, the three decide to head to Florida to stop the proposal. Luckily, Miles isn't thrilled with the idea of having a stepfather, so he decides to accompany them on their zany road trip. Justin Long, Matthew Gray Gubler, and Jesse McCartney provide the voices of the chipmunks. Bella Thorne and Tony Hale co-star. Directed by Walt Becker.