Tire Valve problems of the 2002 Audi A4

The consumers vehicle had two tire failures within the last eleven months for no apparent reason. The manufacturer stated that they did not know why he was having tire failure. Michelin, primacy, size is 235/4517. On June 24,2004, the consumer noticed a loss of tire pressure which was about 1lb or 2 every month. The problem was unable to be figured out. While replacing the valve stem, along with placing the tire back on the rim while trying to re-inflate the tire, the inside wall of the tire blistered. The vehicle was unsafe to drive. The tire was sent to michelin for evaluation. There was a tiny leak in the tire, but that wasn't enough to cause the blister, reevaluation could not determine why the tire blistered. The replacement tire failed on 5-25-2005 while in a parking lot and the tire wall began to separate from the tire. America tire company analyzed the tire, and no cause for the tire failure was determined. Also, this tire was sent for evaluation and the consumer has not heard anything yet. He tried to find out from tire manufacturer and Audi about the recalls, and they would not provide any information.