I'd gone back and watched the video again and that struck me too. I know that no racing game I'm aware of has wind affecting the environment much at all, but GT5 is so darn realistic looking, I think they should keep winds down to 15mph or less, maybe 10. Anything more than that would look wrong, at least for courses with trees by the trackside.
And it's nice that a number of us have commented on how unrealistic cockpit view is. Frankly, the best view I've seen in a racing game in Toca 3's, and that only had a black frame from inside the car, even closer to the windshield than in GT PSP.