Tire Blowout problems of the 2001 Toyota Avalon

The contact owns a 2001 Toyota Avalon. The vehicle has michelin mxv4, size p205/65r15 92vms tires. While driving 70 mph, the rear passenger side tire blew out. The contact stated that he did not drive over anything that may have caused the failure. The tires on the vehicle were replacements that were purchased from costco more than a year ago. He stated that all four tires were leaking air, causing him to place more air in them each week. The failure causes the vehicle to wobble while driving. The dealer rotated and balanced the tires, however, the failure persists. The latest repair on the vehicle was performed on August 27, 2007. The dot number and speed were unknown. The current and failure mileages were 54,000.