DT: CALLER SAYS WHEN 4-WHEEL DRIVE CONTROL IS BUMPED IT KNOCKS VEHICLE INTO NEUTRAL AND THE VEHICLE ROLLS AWAY. WHEN THIS HAPPENS THE 4 WHEEL DRIVE CONTROL OVERRIDES THE PARK GEAR, AND THIS CAN HAPPEN WITH NO ONE IS IN CONTROL OF VEHICLE. CALLER HAS CONCERNS ABOUT HER FAMILY SHOULD THIS HAPPEN WITH CHILDREN IN VEHICLE. THIS CAN HAPPEN WHILE IT IS IN PARK WITHOUT THE KEY IN IT. DEALER SAID ALWAYS USE EMERGENCY BRAKE. MANUFACTURER JUST TOOK NOTES, AND SAID THEY WOULD GET BACK TO HER IN 48 HOURS. CALLER HAS A LEXUS GX470.*AK