Heated mirrors are easy to fab. Buy a set of motorcycle grip warmers on ebay for $10. Pop out the glass and stick the grip warmer element to the back of the glass. poke a hole in the mirror housing for the wire. Put glass back in mirror. Wire to switch. Done.
1966 109 5 door wagon 300Tdi "spermaceti fueled"
1994 RRC LeWiB "ruining the air behind me"
All my troubles are Rover