So, I've been thinking on this same issue for the last few years. I've looked at those add on louvers. Aircraft NACA ducts. Even though if grafting in some Buick GN fender, or GNX fender outlets. Saves cutting the hood. Also 70's Trans Am has a fender outlet. Just another idea, that would not involve a lot of hood rework or structural compromises.
I thought the back of the wheel well area outlet. And out through the fender at a point about half the door height.
I was thinking " I'll just make a path of least resistance. The air down the side would have lower pressure therefore the higher pressure under hood air would drawn to the easy exit. Just a thought.