I've always plugged my tires myself. Sometimes the plug will leak slowly, requiring air to be added every week or so. Anyway, i've usually sovled that problem by adding a can of fix a flat also. It's always worked in the past. This time i put a whole bottle of truck and suv stuff in my crx tire. Big mistake. It was obviously to much. When i get to 50mph, it starts bouning like heck. Off to the tire store i go today. Hopefully they won't charge to much dismount, get all of that crap out,patch it from the inside, and rebalance it.