Inspecting the bottom of the seat from my '13 48, I noticed no rubber bumpers for the seat to rest on, which put a lot of my weight on the fender nut I figured. A stop to the hardware store I found these rubber stoppers which slid right in the existing holes with some tire lube after I drilled them out just a little bit. Viola! Less weight on the fender! Peering in from the side, I noticed they still didn't touch the frame, but would with my weight on it. I could then relax knowing I relieved some stress on my fender and improved the function of my seat for just a few bucks.
Looks factory even!