[Flakbadger]

My hollow a-pillar is filled with an airbag... I don't know that you could move enough air through the pillars to make it worth your while. Also, my a-pillars make more noise than any other part of my car at freeway speeds as-is. I can't imagine pumping more air through would be any better.
Not to pee in the punch, but that's my opinion. Ducting the air into the lower pressure areas like the wheel wells would probably be a better use of effort.