90781-09 - DAMN! Just checked the fitment guide, and this is for '09 - looks like I needed 90781-93 with 49087-01 and 46548-03. Now I don't feel like such an idiot trying to make them fit.
I have an '07 parts book and that is not in it. Also there is nothing like that on my bike. The support rail that goes under the bag attaches near the bottom of the fender and the side protection rails attach to the piece already on your bike (the one with the square hole) That piece LOOKS like it should fit, but I share your confusion. Sorry.
90781-09 - DAMN! Just checked the fitment guide, and this is for '09 - looks like I needed 90781-93 with 49087-01 and 46548-03. Now I don't feel like such an idiot trying to make them fit.