[Drivesthebeast]

You can buy stuff like that made by 3M, and can buy it from UAP/Napa. It's NOT rubberized undercoating....it's an actual rocker aerosol. It comes in a tanish/creamy colour that you would have to paint over. My first car had it's orignal rockers rot out, and we rebuilt them with fiberglass and steel, and then we ended up using self-etching primer, followed by the rocker aerosol, and then painted them flat black. They looked OEM when finished, and yeah, stones bounced off them instead of chipping them.

I think this is the same process you wanna do to your car, if you are adimate about having the 2-tone again.

Hope this idea helps.