Plot hole: Just before the bomb explodes at the beginning of the movie, the guard is looking for the car playing 'don't worry baby' on it's stereo. In the final timeline the disaster has been averted, the bomb having gone off, and the ferry docked. After this, when Carlin is in the car, the same song is playing, but the bomb was set to a timer.
Suggested correction: That's why the movie is called Deja Vu and thats why Carlin gives the girl such a strange look. The song triggers a feeling of Deja Vu for him and it almost feels to him that he knows her. Besides, a different station could have been playing the song.
Suggested correction: The first time it plays comes off the radio. The second time we hear it mid-play. It could have come from a different station, the same station could have played it again later, or a CD or cassette being played in the car.