Where's the Defroster?

I saw where a fellow Bradley owner opened up his defroster and found a 12V ceramic heater that would blow into the vents to warm up the window area.
The original VW Beetle had the heat coming from the gas engine and you'd open up a vent to have the heat travel from the rear along a pipe to come into the passenger area.
This defroster/fan is pain in the butt to get to. You have to lay upside down on the bottom of the floorboard and try to get the screws out. Then because a couple screws were completely rusted, I ended up ripping it out.  Not as bad as it sounds.  This whole box is under the hood vents and they're not accessible in any way except through the firewall.  BTW I had dropped a wrench down the vent and was finally able to retrieve it, along with probably 15 years of dirt and leaves.

Here's the front side, the side you get to see upside down.  The ducts attach in the front then go straight up to the windshield.

Here's the other side, this sits in the box, inaccessible except by the front.

So...where's the defroster?  I guess I don't get one?  Maybe the defroster was only for the GTEs?  WA state law requires a defroster in every car.  Well, let's add a 156V electric heater.  These gems will take a variety of voltages and can get quite toasty.   With that fan in the back, it should work very well. So... do I add two heaters?

Or just one?

One that's directly in front of the blower?  Either way, I'm going to have to glass the heater in place so it doesn't move and the air blows directly through it, not around it. Another consideration - this only provides heat for the windshield, there's no option to vent the air elsewhere with a dampener.  Maybe install a second heater in the back to go to the feet? Hmmm.