I have a 860m and it’s unbearable in summer even with shorts on. Nice in fall and spring but not summer.
I took the seats and plastic off as if you were going to change the belt and I went to Menards and picked up some reflextic. It’s flexable, I wrapped up behind seats to top of air cleaner box, in front of compartment behind my feet and top. Around shifter and seatbelts. I used heat tape to seal everything and screwed the plastic compartment screws right thru the reflextic. I sealed up the battery and fuse compartment up but I have a utility knife with me if I have to cut a opening to get to them, and have some heat tape with me also to tape it back up. I would say it’s about a 90% difference in heat reduction.