So I'm traveling this week. Rented a car, and this morning, I found one of the tires flat. The rental firm said to take it to a shop, and they'd pay if it was a defective tire or valve, but not if it was damage to the tire from a nail or accident.

The guy at the shop dunked the tire and saw bubbles coming from the inner sidewall where there was a tiny pinhole. He said that the tire probably delaminated or has a defect from the factory, and since the leak was in the sidewall, it couldn't be plugged -- rental agency paid for a new tire with a credit card over the phone, no problem.

Has this happened to anyone? How common is this? I've never encountered something like this in any of my own cars. I wonder if dumping a bunch of "Slime" into the tire would have fixed it.