Hi,
I did install them on my 2016 F3T.
I installed both front and rear heated pad and installed switch where rear heated grip switch should go. There a plug there you just have to remove.
On the other side, I drilled a hole at the same place.
left switch is for front seat and right one for rear seat.
It's still pretty easy to use your left hand to reach the switch for driver seat. Or I just tell my wife to turn it on or off.
View attachment 181618
View attachment 181619
Maybe I can have used the wires for the heated grip for my heated seat pads, but I just end up passing 2 new wires (fused) directly from the battery to a relay under the passenger seat. That relay can only be turned on when the Spyder is running (getting the signal from the passenger heated grip connector).