Engine Exhaust System problems of the 2011 Buick Lucerne

2011 Buick Lucerne. Consumer states issues with vehicle and describes a crash the consumer stated there was a very loud noise emitting from the vehicle which lasted about 30 to 60 seconds. Two days later, the noise returned, but it sounded as though steel was breaking. A week later, the consumer and his wife were involved in an accident. The police stated the consumer made an illegal u-turn and therefore, the vehicle was t-boned. The consumer believed he and his wife were inhaling toxic fumes and possibly passed out. After the accident, there was a muffled explosion that came from the rear of the vehicle. The vehicle was totaled.