Just a general piece of information for anyone riding in winter.
If you're tempted by a pair of bar-muffs (not sure what they'd be called in the US), these Givi muffs linked below, WILL go over the R1150 series handguards.
Just bought some secondhand off UKGSer....Toucano R319N....fit over GS handguards and mirrors no problem.
Never used them before, there brilliant! Went out the other day, temp was +1 and had to turn off the heated grips, and I was wearing my GS dry summer gloves. Turned the grips back on about 5 pm on the way home as the sun had gone down. They may well look geeky but they sure do work.
Be interesting to see how they fare in heavy rain as there fleece lined and I'm sure it must get wet inside eventually. Time will tell.