Originally Posted by Bathead
That still would have done nothing to slow them down enough to avoid at the very least a number of broken bones. (if not outright death, considereing it looked like the party was held in the penthouse of a high-rise building) There is nothing in that scene to indicate that's why they survived the fall.
What I see when I watch the scene is Batman, while holding Rachel, extend one arm (enveloped by cape) up. Not only do they spin due to the air catching in the cape, but also you can hear the cape flapping. If I pay very close attention, I do notice them slow down quite a bit before smashing the roof of the car (which not coincidentally also cushions the fall considerably). Realistic? Search me, but a close visual and aural inspection of the scene shows that (to me) it wasn't a complete free fall.