Tire Valve problems of the 2006 SAAB 9-3

The contact owns a 2006 SAAB 9-3 equipped with replacement michelin tires, tire line: primacy mxm4, tire size: 215/55r16, and dot number: b9vm87dx2716. The contact stated that while her son was driving at 65 mph, the vehicle was shaking and he could not control the vehicle. As a result, he pulled over to the side of the road where he noticed that rear driver side tire was flat. Roadside assistance was called and able to change the tire. The contact stated that issued occurred on a front tire several months prior but was unaware if it was on the driver's side or passenger side tire. The vehicle was taken to the sears store where tires where purchased and they diagnosed the issue as the stem valve. The tire was replaced. The contact mentioned that several months later the issue recurred but was unaware if the tire was on driver's or passenger front, the vehicle was taken to an independent tire shop where the diagnoses was the stem valve was cracked and it was replaced. The manufacturer was not notified of the failure. The approximate vehicle failure mileage was 94,000 and tire failure mileage was unknown.