This worked out pretty well, and I even DID take a before/after, which hopefully attaches to this reply.
It works best around the outer edge of the rim, where the contrasting black of the tire right next to the painted area does the best job of hiding it. I had less success with an area closer to the center (in the picture), because it was hard to hide the brushstrokes (it's not a very good brush at all - like a 'liquid paper' brush). Anyway, if most of your rash is on the circumference of the rim - highly recommend this paint!
Karma #328: Shadow on Monsoon Tri-tone