STOPPED AT STOP LIGHT. CAR STATIONARY. OUT OF NOWHERE ENGINE ACCELERATES ON IT'S OWN AND RUNS INTO AN 18 WHEELER TRUCK THAT IS PASSING THROUGH IN INTERSECTION. I TRIED TO STOP FORWARD THRUST BY PUTTING BOTH FEET ON BRAKE, TAKING OUT OF GEAR WHICH WOULDN'T BUDGE, THEN PULLING UP ON HAND BRAKE. AFTER HITTING BACK TRAILER WHEEL OF TRUCK AND JEEP RAISING BACK END OFF GROUND FROM IMPACT ACCELERATION STOPPED AND ENGINE IDLED.SUDDEN UNINTENDED ACCELERATION. MANUFACTURER DEFECT. ACCIDENT STILL UNDER INVESTIGATION BY INSURANCE COMPANY. JEEP TOWED TO BODY SHOP.