Today, I brought my car into Discount Tire and had air put in all my tires. All of them were in very good shape. I was able to drive my car fine with no problems. Tonight, I saw that one of my tires was completely flat. I didn't have any kind of a blow out because when I parked the car in it's normal spot it was fine. How can a tire go flat in a matter of hours? Even if it had a nail in it, I'd still have enough air at least to drive it over to the tire shop in the morning.