I am requesting NHTSA assistance regarding a serious and recurring braking safety concern involving our BMW X5. We initially reported braking problems to BMW and brought the vehicle to the dealership for evaluation. We were advised that the vehicle was operating normally. Subsequently, a brake related recall was issued, and the vehicle underwent recall related service. Despite this, braking concerns continued. We again reported the problem and were advised after evaluation that the vehicle was operating properly. There were subsequent incidents involving abnormal braking behavior. During 1 incident, my wife was slowly parking the vehicle when it did not stop as expected despite repeatedly applying the brake pedal. The vehicle continued moving and collided with a wall before eventually stopping. We have also experienced abnormal brake vibration and other concerning braking behavior. Because of these repeated safety concerns, the vehicle is currently the subject of pending lemon law litigation involving BMW North America. Most recently, we returned the vehicle to the BMW dealership because of the braking and safety concerns. The vehicle remained there for approximately 4 months. We have not received a clear explanation of what diagnostic testing, inspection, repair, or corrective work was performed during this extended period. We were then informed that the vehicle was ready for pickup. When we went to retrieve it, it was covered with substantial dust and had very low tire p