I STARTED MY VEHICLE, IN MY GARAGE, TO WARM IT UP FOR ITS FIRST SCHEDULED MAINTENANCE AT THE DEALERSHIP. THE PARKING BRAKE WAS ENGAGED FROM MY LAST USE OF THE VEHICLE THE NIGHT PRIOR (I ALWAYS APPLY THE PARKING BRAKE BEFORE EXITING MY CAR). AS MY HIGHLANDER WARMED UP, I BEGAN REMOVING A FEW PERSONAL ITEMS SO THAT THEY WOULD BE OUT OF THE VEHICLE DURING MY SERVICE AT THE DEALERSHIP. I PLACED MY PERSONAL ITEMS AT THE END OF MY GARAGE, ADJACENT TO THE FRONT-END OF THE VEHICLE. AS I TURNED FOR MY 3RD TRIP BACK TO GET THE LAST OF MY PERSONAL ITEMS OUT, I SEE MY HIGHLANDER STARTING TO ROLL BACKWARDS. I WAS AT THE FRONT-END OF MY VEHICLE WHEN IT STARTED MOVING IN REVERSE. I WAS UNABLE TO SAFELY ENTER THE VEHICLE WHILE IT WAS IN REVERSE MOTION. MY VEHICLE BACKED UP OVER A CURB AND MADE IMPACT WITH BUSHES AND A BUILDING STRUCTURE. I QUESTION IF FAULTY CONSTRUCTION OF THE PARKING BRAKE ALLOWED IT TO DISENGAGE AND INDEPENDENTLY INITIATE MOVEMENT IN REVERSE. *LN *TR