Audio problem: When Phil is playing the piano with the jazz group, we hear three glissandos (dragging of the fingers over the keys starting from high to low), yet we see his hands only do one. We hear the first two happen while we see his hands playing something different.
Audio problem: When Phil is dressed as an outlaw and pretending to be "Bronco" his Clint Eastwood impression voice is out of sync with his lips.
Audio problem: At the party when Phil is playing the piano, there are several shots of the other band members. Multiple times they are seen playing their instruments, but they are never heard. The most obvious example is right before Phil finishes up his set. The saxophone guy is playing but you never hear it.
Answer: We know the police car survived because unit 2 is the car that followed them onto the tracks, and unit 2 is also one of the cars present when they are stopped (though it came from the wrong direction). The movie doesn't explain how the car survived so it is left to the viewer's imagination.