CAR WAS DRIVEN OUT OF NEW CAR DEALER WITHOUT INCIDENT BY DRIVER WITH 50 PLUS YEARS EXPERIENCE. APPROXIMATELY THREE TO FOUR MILES INTO TRIP CAR EXPERIENCED SUDDEN UNINTENDED ACCELERATION AFTER GOING THROUGH A TRAFFIC LIGHT. CAR PROCEEDED INTO WOODED AREA AND HIT TREE CAUSING LOWER LEG INJURIES TO DRIVER AND MODERATE TO SEVERE DAMAGE TO CAR. DRIVER WAS NOT ENTRAPPED UPON EMT ARRIVAL. ENGINE RETURNED TO NORMAL IDLE SPEED. DRIVER IS CONFIDENT CAR HAS PROBLEM WITH VEHICLE SPEED CONTROL AND /OR ENGINE COMPUTER. CAR TRAVELED AT OVER 40 MPH DURING INCIDENT AND COULD NOT BE STOPPED THROUGH NORMAL BRAKING ACTION.