I WAS PARKED WITH THE ENGINE RUNNING (AND GEAR SHIFT IN PARK) IN DRIVE-THRU AT BANK. I MOVED THE GEAR SHIFT TO 'DRIVE' WITH MY FOOT STILL ON THE BRAKE, AND WITH NO WARNING, THE ENGINE MADE A REVVING/RACING SOUND, AND THE CAR SHOT FORWARD AT GREAT SPEED. THE CAR TRAVELED THREE CAR LENGTHS (IF PLACED SIDE-BY-SIDE) AND AS I TURNED LEFT TO SWERVE, THE CAR HIT ANOTHER CAR CAUSING IT TO SPIN AROUND ABOUT 180 DEGREES. I WAS APPROACHING THE INTERSECTION AND IN ORDER TO STOP THE CAR, I COLLIDED WITH THE CURB AND TURNED OFF THE IGNITION AND THE CAR FINALLY CAME TO REST. THE REVVING/RACING NOISE CONTINUED FOR THE DURATION OF THE INCIDENT, AND EVEN THOUGH I WAS BRAKING, THE CAR NEVER STOPPED UNTIL I HIT THE CURB AND TURNED OFF THE IGNITION.