With the white-whale I was given a pair of wing mirror heat pads. I wasn't going to bother fitting them as they are probably more trouble than worth, but matey challenged me to a dual of him and me fitting them to our trucks and see who does the neater install. I won and then he copied me !
I installed into the stock wing mirror with zero wiring being visible. Will have to wait till winter to see if they have any value, am wondering if I can turn them face up and fry egg on them...

They have been wired to heavy side of the rear window demister relay via a 10amp fuse.