general problems of the 1996 Chevrolet Lumina

Had a flat tire, and the dealer told the consumer had dry rot, and should change the tires. They are 70,000 miles on thre tires, and they have been used for 3 years and 28,000 miles. Yokohama tires.

While driving about 45 mph, when rear left tire collapsed, falling apart from vehicle with rims and tire together. Consumer lost control, crashing into a wall. Dealer was contacted, please provide more information.