AFTER STARTING MY CAR I WENT IN MY HOUSE TO GET SOMETHING. MY CAR SLIPPED INTO REVERSE AND ROLLED DOWN MY LAWN ACROSS A BUSY STREET AND HIT A TREE. THE EMERGENCY BRAKING SYSTEM DID NOT ENGAGE. I WAS ABLE TO DRIVE THE CAR BACK TO WHERE IT WAS PARKED. I THEN TESTED TO SEE IF I COULD HAVE ACCIDENTALLY PUT THE CAR IN REVERSE WHEN I GOT OUT IT. IT BEGAN TO ROLL IN REVERSE AND I WASN'T TOUCHING THE GAS. I COULD NOT HAVE GOTTEN OF THE CAR IF WERE IN REVERSE BECAUSE IT WOULD HAVE BEEN ROLLING. APPARENTLY WHEN THE CAR IS IN A PARKED POSITION IT CAN SLIP INTO REVERSE.