I was told to hit a car window on the lower corner, away from the A post, to break it out.
I'm told that the trick is to keep the window from bowing from the strike instead of shattering. The corners are better than the center for that reason. The lower corners are better because the window is held more firmly there. Why away from the A pillar I have no idea.
chaosmagnet "never broke a window...on purpose"