Took a GS Rally Sport out for a demo yesterday. In a conversation with the sales guy afterwards, he thought it would be unlikely that you could fit an Autocom SPA unit under the seat of the bike. This surprised me. The dimensions of the SPA are 14 x 7 x 2.5 cms. I did not have time to take the seat off the demo bike to check this. Anybody know how much space there is under this models seat and whether the unit I have mentioned could fit?