on the stock Vista Cruiser the tail gate flips down, and the window up.
the T-Bird has no tailgate, so if you made the rear window the same height as the side windows, you would have a very high lift over to put things in the back.
I meant the outer styling, not the whole thing. They successfully put a wagon top on a T-bird - that's some heavy fab and real vision, but then kinda punted on the back end.
We took a few family vacations in a '69 Vista Cruiser. It was that weird olive metallic green with wood paneling. Yeah - massive tailgate. Massive car! Ours only dropped like a tailgate, some had a gate that would also swing out and I think a reverse back seat. The reverse seat might have been Ford though....