Go to the scene where Dave Seville has just seen Alvin's hat, and then Alvin in the back of Claudia's limo. Dave screams "My kids are in trouble!" and the officer takes him in the police car. The blunder happens after the cop turns the ignition.

Pause the movie when you get a front view of the cop car; it MUST be RIGHT AFTER the scene above. The light bar will have the red lights on the left and blue lights on the right.

Pause in ANY OTHER scene in which you can see the front of the car. No matter WHICH scene you pause in, the lights will ALWAYS have the BLUE lights on the LEFT and the RED lights on the RIGHT.

It only happens once; why???