Cooler air intake works to a degree. The intercooler on my TT turbo drops the intake charge 42 degrees. I measured the temp.
On a naturally aspirated engine, all that would do is freeze up the induction system. My Holley would literally ice up with the air temps at around 40f. The heat crossover was blocked.
The trade off of a couple of extra hp vs. practical use isn't worth it in my view.
With the Pantera, a few have gone to Pontiac Fiero roof scoops. Ram air is useless. It's ducting for cooler air that you want...again, to a degree.
Considering the huge blind spots this car has, why make it worse? The bat ears block an important view point on the Pantera. You could go to clear lexan as a solution though like Ferarri did on the F40.
Even so, it's just and academic exercise. No matter where you put ducting back there, it interferes with something else.
Quite a few Pantera owners found that just removing the rear side glass, accomplishes the same thing and it blocks nothing.