The contact owns a 2006 Audi A4. The contact stated that while driving approximately 45 mph, the wife crashed into the rear of a second vehicle. During the crash the front driver side air bag did not deploy, however, the passenger side airbag did deploy, and both the front and rear driver side and passenger side headrest restraints activated. The contact indicated that no passengers were present in the vehicle during the crash. No injuries were reported. A police report was taken at the scene and the vehicle was towed away. The cause of the failure was not yet determined. The manufacturer was not contacted. The local dealer was notified. The failure mileage was 160,000.