If you're replacing a piece on the stock rear seat cowl, you'll have to go through a dealer unless you can find one on ebay or something. (If you could post pics of what you're actually referring to, I may be able to help you out a little more.) As far as a "Crash Cage" goes, it's pretty simple to have one made or fabricated to your liking. Do you actually want a "cage" type protection or frame sliders? Are you stunting or just for casual touring/riding?