I second what Dixter said, I've read many times here about the rear window popping out, but never heard the air bag theory, and with all due respect to the poster I kinda doubt it, having been through a "significant airbag experience" in an LS400 I can tell you that the danger to your ears is from noise, a shotgun shell type of noise that inflates the airbag, the airbag itself does not displace any significant amount of air, only about the size of a small pillow and it instantly deflates again, and of course it does not explode, so there is no sudden explosion of air in the cockpit, only noise.