general problems of the 2020 BMW Z4

Was in a drive thru on 9/6/2020 waiting our turn. Approx. 7 cars in front of us. As we are slowly moving up to order, car in idle, foot on brake. As we are moving forward, when we were up to 3 cars, still idling and foot on brake, the car had fully accelerated, brake not holding the car, inching forward due to the force of the acceleration. Tried to shift into neutral, went into reverse. Tried again to shift into neutral, went into drive, still inching forward, at this time I pushed the off button to stop the car. Result of collision with the vehicle in front of us. We have photos but not on this computer.