I carry one of those kits on my motorcycle, I don't know why it never occurred to me to carry it in my car. Seems so obvious. The problem with the fix-a-flat goo is that it can ruin your tpms sensors, and I heard it leaves a mess inside your tire making it impossible for tire shops to plug it. With these plugs, the tire shop can just remove it and put a permanent plug in. But I wonder if you can plug a rear tire with this without taking it off the car, might be hard to get at the hole especially on a low car.