CAR WAS PARKED ON NEAR-LEVEL SURFACE OF DRIVEWAY. CAR WAS LEFT IN NEUTRAL (MANUAL TRANSMISSION) AND PARKING BRAKE WAS SET. DOORS WERE LOCKED. CAR BEGAN TO ROLL 165 FEET DOWN DRIVEWAY ABOUT 20 MINUTES AFTER USE. CAR RESTED IN A FENCE POST. DEALER CLAIMS THAT CAR SHOULD BE LEFT IN GEAR BECAUSE THE PARKING BRAKE SYSTEM ON THIS CAR IS HYDRAULIC, AND WHILE THE CAR IS DRIVEN, THE REAR DISC BRAKES HEAT UP, AND WHEN THE CAR IS PARKED, THE BRAKES COOL DOWN. THE SAME BRAKES THAT COOL DOWN ARE THE SAME BRAKES THAT HEAT UP. WHEN A BRAKE PAD HEATS UP, IT EXPANDS, WHEN IT COOLS DOWN, IT CONTRACTS. MY PARKING BRAKES FAILED BECAUSE THEY COOLED OFF AND BECAME INOPERABLE, CAUSING THE CAR TO ROLL ALL ON ITS OWN. I WAS NEVER INFORMED THAT THE PARKING BRAKE SYSTEM ON THIS CAR WAS NOT A SEPARATE DRUM BRAKE, AND I WAS NEVER ADVISED BY THE DEALER DURING DELIVERY TO LEAVE THE CAR IN GEAR WHILE PARKED BECAUSE THE PARKING BRAKE WILL BE USELESS AFTER EVERY TRIP.*AK