SOMETIMES WHEN SLOWING TO A STOP, THE CAR ENGINE ACCELERATES. I HAVE TO STEP ON BRAKES VERY HARD TO KEEP THE CAR FROM GOING FORWARD. ON NOVEMBER 5, 2015, I WAS SLOWLY PULLING INTO A PARKING SPACE AND THE CAR ACCELERATED, I STEPPED ON BRAKES REALLY HARD BUT THE CAR WENT FORWARD...INTO A STONE WALL. NO ONE CAN TELL ME WHAT THE PROBLEM IS SO I WIND UP STILL DRIVING A CAR THAT MAY DECIDE TO LURCH FORWARD INTO TRAFFIC, A WALL, ANOTHER CAR. THE VEHICLE IS AT THE DEALERSHIP NOW AND I AM WAITING TO HEAR ABOUT THE STATUS. I WAS TOLD BY THE SERVICE CENTER PERSON TO CALL GM AND TELL THEM THAT I HAVE A POTENTIAL PRODUCT LIABILITY CASE. I AM AT A LOSS AT WHAT TO DO.