WAITING IN LINE TO PICKUP PRESCRIPTION, STOPPED WITH FOOT ON BRAKE AND VEHICLE ACCELERATED INTO CAR APPROX 15 FT IN FRONT OF ME. EYE SIGHT BRAKING DID NOT STOP CAR, NOR DID IMMINENT COLLISION WARNING ENGAGE. CAR IS AT DEALERSHIP AND THEY CONDUCTED TEST; FOUND NOTHING. AWAITING SUBARU ENGINEER TO PULL AND CHECK "BLACK BOX".