I STARTED THE VEHICLE, THE SYNC SYSTEM WENT THROUGH A RESTART, KILLING THE ENGINE AND TURNING OFF THE DASHBOARD PANELS. IT HAD HAPPENED BEFORE ON A LEVEL SURFACE, BUT THIS TIME I WAS ON A 10-15% GRADE. I STOPPED AGAIN, TURNED THE VEHICLE OFF AND RETURNED ABOUT 15 MINUTES LATER. I WAS ON A SLIGHT HILL, WITH THE ELEVATION LOWER IN FRONT OF THE VEHICLE. I STARTED THE CAR AND STEPPED COMPLETELY OUT WITHIN 10-15 SECONDS. I STEPPED OUTSIDE THE VEHICLE, WHICH HAD BEEN RUNNING FOR 10-15 SECONDS. THE HATCH WAS OPEN AND TWO FRIENDS BEHIND COULD CLEARLY SEE THROUGH THE VEHICLE, TO KNOW THAT I DIDN'T TOUCH THE PUSH BUTTON TRANSMISSION. THE VEHICLE STARTED ROLLING DOWN THE HILL. I JUMPED IN, BUT THE BRAKES DIDN'T WORK AND THE INSTRUMENT PANEL WAS DARK. IT STOPPED ROLLING WHEN IT COLLIDED AGAINST A PARKED TRUCK APPROXIMATELY 50 FEET IN FRONT. THE ENGINE WAS OFF WHEN IT STOPPED. I THINK THE RECYCLE OF THE SYNC SYSTEM CAUSED AN INTERMITTENT MALFUNCTION OF THE ELECTRICAL SYSTEM, CAUSING THE BRAKES, STEERING AND PUSHBUTTON TRANSMISSION TO BECOME NON-OPERABLE. THIS RESULTED IN DAMAGE OF $8568 TO MY MKC AND OF $1512 TO THE PARKED TRUCK. SINCE THIS IS AN INTERMITTENT INCIDENT, IT CAN'T BE REPLICATED AT A DEALER EVEN IF IT HAPPENED, IT WOULD BE ON A LEVEL SURFACE AND WOULD NOT ROLL. I HAVE DRIVEN THE VEHICLE FOR AN ADDITIONAL 7 MONTHS AND 8,819 MILES. THE CURRENT MILEAGE IS 27,474. DURING THAT TIME, THE VEHICLE HAS STARTED AND THEN GONE THROUGH AN ELECTRICAL RECYCLE WHICH CAUSED THE