Portawalls:
They are difficult to install so that they lay flat against the side wall. The tire needs to be broken away from the rim and as a small amount of air is introduced into the tire, begin to seat the portawall on the tire and under the rim, you'll need to tap it under the rim edge with a rubber mallet that's wrapped with a clean tee shirt until it's even all the way around the rim. A genuine PITA ass to do. Problem with them is that in a short amount of time, the natural oils in the tire compounds leach into the white portawall. ~Alan