my wife got a flat. i didn't have time to mess with it so i took it to a tire place. they told me they couldn't find anything wrong. So aired it up put it back on the car. My wife drove it to work the next morning, called said it was flat again. I found a puncture and patched it. trouble is, she drove to work with the tire almost flat. the side wall and has small crack all the way around. no missing rubber chunks, no visible belts, just a hair line crack. the tires will need replaced in spring, and with Christmas here i'd hate to have to buy a new set now. I also don't want to by one new tire then three more in 6 months. will the tire be ok or is it too dangers to risk?