2009 Chevrolet Traverse drivetrain & axles problems

1st. My wife was pulling out of a parking spot and had to stop quickly, then when she proceeded to leave again by letting off the brake - the car rolled forward on a slight incline and hit the car parked next to her. When she removed her foot to the gas - nothing she could do to prevent this incident. 2nd. While in the drive position on a hill at a stop sign or traffic signal, I removed my foot from the brake. The vehicle began to roll back almost hitting the vehicle behind me.

Tl* the contact owns a 2009 chevrolet traverse with hand-controlled mobility equipment. The contact stated that while driving approximately 10 MPH, the vehicle was hesitant to accelerate. The vehicle was taken to the dealer for diagnosis and also to the mobility equipment mechanic. Neither technician was able to diagnose the failure. The manufacturer was made aware of the failure. The vehicle was not repaired. The approximate failure mileage was 35,000.