It’s rehearsal time. The Anaheim PD officer takes a swig of bottled water and sings a few bars of “Don’t Stop Believin’” to clear his voice. The camera starts to roll and Shane Spielman, a motor officer in the APD’s Traffic Unit, goes to town. He welcomes viewers – for now, just his crew of five – to the latest installment of “Ask a Motor Cop.” Today’s segment will be relatively elaborate, with Sgt. Rick Boyer undergoing no fewer than four costume changes during the nearly nine-minute segment to promote an upcoming motorcycle safety expo. Watching Spielman as the camera…