I want to add PL, PW, and power mirrors but also would like to add heating elements to them. Winters are quite frosty in Idaho. Deschlong has a good writeup but did the folding mirrors, but those are expensive nowadays and I can go without them. It's the heat and power I'm after. Are power mirrors from the Ex pre-wired for heat? If not is there a way to run electricity to the heating elements?