2013 Nissan Murano Tires & Wheels Problems

While driving, the rear arm connected to the rear driver-side wheel broke off. According to my Nissan dealership diagnosis, this was due to excessive rust/rot of the whole subframe. The 2013 Nissan Murano rear arm cannot re attach the wheel to the sub frame due to so much rust/rot on the sub frame. The whole subframe would need replacement. When doing an estimate on fixing, Nissan called and stopped the estimate when replacement of the subframe, fixing of the arm, and additional rust/replacement exceeded the value of the car. My son and I were driving on the road when the arm broke off the rear wheel, the wheel went sideways and we skidded to a stop, so our safety was at risk. There were no warning lights or signs of this happening. While driving on the road, my car felt unstable then seconds later the arm broke off. The car was at Nissan 4 months prior to have work done, I had them do a multipoint inspection when there was a problem/engine light with the vehicle and it would not go more than 15mph. Nissan fixed loose RF hub, plus they replaced a right and left front sway bar. This is right on the sub frame, there was no warning given to me that the sub frame was rusted or could give out.