TODAY, SHORTLY AFTER STARTING THE CAR, AN AIRBAG DEPLOYED. THE CAR WAS PARKED IN MY DRIVEWAY AND NOT IN MOTION, AND THERE WAS NO IMPACT. THE AIRBAG DEPLOYED FROM THE OUTBOARD SIDE OF THE PASSENGER SEAT. I WAS SEATED IN THE DRIVER'S SEAT. THE PASSENGER SEAT WAS UNOCCUPIED AND ITS SEAT BELT WAS UNFASTENED, HOWEVER A LAPTOP AND SOME OTHER LIGHTWEIGHT OBJECTS WERE IN THE PASSENGER SEAT.