You're staring at a flat tire with your keys in hand, wondering if "just this once" will ruin a $150 tire or get you to safety. It's 7 AM, you've got somewhere to be, and the tire looks... kind of flat. Not pancake flat, but definitely not right. Here's the thing — driving on a flat tire isn't a yes-or-no question. It's about how flat, how far, and what you're risking. If you need...