Yes, the A-pillar is ideal, but the 80 has space limitations. In addition, the A-pillar is closer to the driver than most other cars, thus compounding the problem.
There's no room in the A-pillar for proper imaging. I think a 1" tweeter is what I have, and as you can see there is very little room for swiveling/tilting. Even with swiveling/tilting, it would need to be swiveled/tilted 30 degrees or so. At that point, you're better off making a tweeter pod for them in the A-pillar.
http://imageshack.us/photo/my-images/846/img1457oo.jpg/