And what the hell is ithis?

[Ghoste]

Dropped out from under my dash.  It's copper and about an inch long.  Clearly a terminal of some sort but for what?

[twodko]

Ghoste,

I'm pretty sure that's one of the clips that slide onto the heater box defroster outlets.
I believe there are four altogether (?). Once they are in place the defroster vent hoses
slip over the them and are captured by the barbs

[Ghoste]

Yes, I think you are right.  It dropped out when I was moving hoses to put the heater box back in. (I was jostling wiring too and it being copper...)

Thank you thank you.