I've been a loyal patron of Greg's for years, but have had 4 blowouts in 3 years with their used tires. They claim I'm the only one, that everyone else is happy with their used tires. I'm wondering. Anyone else have any unexpected problems with their used tires? A friend is thinking that they are perhaps getting substandard shipments of used tires, that were poor new tires to start with. I understand used tires are a gamble, but 4 in a row? I had never had a blowout in my life previously - also rarely had ever put on used tires.