I finally got my IQ to RMK seat conversion done...well almost. The seat was off an 05 I believe. I decided to use the storage box that came with the IQ so that I would have a place to put a few tools ect. The mount was too short, so I used (2) 3/4 inch nylon cutting boards, epoxied them together, and cut them to match the bottom of the storage box, then drilled through them and mounted them under the box to the tunnel. To clean up the look I bent a piece of aluminum (long part of a drywall square) and riveted it around the base. Turned out pretty good I think. I do like the look of the OP's better with the open underside, but thought the functional storage would be useful.