The contact owns a 2023 Mercedes-Benz GLC300. The contact stated that while the vehicle was parked, and the contact and his wife were removing groceries from the rear of the vehicle, the tailgate was independently lifted due to the design of the keyless entry feature. The contact and his wife continued to remove items from the rear of the vehicle and the tailgate sensor became enabled, and the tailgate closed inadvertently, striking the contact's wife on the head. The contact's wife sustained a knot on the head that remained for a week. The vehicle was taken to the dealer. The contact was informed that the feature could not be deactivated unless the contact chose to deactivate the entire keyless sensor feature. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The manufacturer was made aware of the failure and the contact was informed that the option would be to deactivate the entire keyless sensor. The failure mileage was approximately 1,000.