Who's stuck a rear defogger in their A-body?

Ol'forest said
Think of making my car abit more user friendly during winter. A rear defroster sure would help sometimes in this foggey place I live.
I have a few questions though.
Firstly the only dart rear windows I've seen with factory defogger elements, have been damn pricey, but has anyone put a rear window from say a mid 70's dart in to a late 60's dart?

Are you talking about rear windows with a heated grid of elements made into them? I think 1976 and maybe 1975 on Darts they offered a rear window with a heated element. Like on new cars. Pretty rare piece. And hard to find one that has been removed carefully not to damage the connections. It would have come out of a 2door hardtop Dart and those back window are the same 67-76. IMHO, those would be worth it and would work.

The other option is the defogger blowers, that go in the rear speaker hole. Do they work?

I've put one in my 68 Barracuda notchback when I lived in Iowa. Those have two seperate ducts instead of one thin duct outlet in the center. If you are referring to the blower motor that have a coil that looks like a heating element, it is NOT. It's just a resistor.

Those are the factory ones. No, they do not work very well. If you can get one for under $50 just a try. $150 or more, not even worth it.

Do they heat the air?

No. Don't be fooled by the coiled elements. That is a just a blower motor resistor. It does not heat the air.

Or is it just a blower?

Yep, just blow air from the interior compartment sucked in from the speaker grille back onto the window.