As long as your heater elements are in working order, AB's seat heater activation kit (switches and switch panel) will get them to work.

 

AK, you have heated mirrors, the heater elements only work when you turn on the rear defroster.

If you use the heated seat switch from AB it will look factory, why poe dunk your ride?

Pat-check with your insurance agent, if YOU add a heated windshield and then it needs to be replaced not all insurance compaies will cover the added cost of the new windshield.
I have full glass coverage on both of our cars, but it only covers "factory" glass.

 

Last time I used my rear defroster it was in the middle of a blizzard and there was nothing around to see in my mirrors so I didn't really pay attention.

 

Well technically Spike, the heated windshield is factory glass. How's the insurance company to know that your truck did or didn't come with it from the factory.

 

I do not know if thay could tell or not, I am just saying it might be worth considering.