Cruise Control problems of the 2013 Mercedes Benz E350

While parallel parking in front of a small restaurant in a large north texas city the vehicle quickly accelerated backwards at a high speed backwards, climbing over a sidewalk curb an then climbed over a nearly 3 foot high retaining wall. The rear end of the car rested on top of the retaining wall. If the retaining wall between the side walk and the restaurant had not stopped the vehicle it would have likely continued to pick up speed and gone through the restaurant. May have been the cruise control mechanism or related acceleration system.