I can't imagine the little vents doing much in a car. On a motorcycle, they do increase air circulation, but you've got ram air on the front and a vacuum on the back to make them work. Also, on a bike, you've usually got the faceshield to keep the windblast off your eyes. In the winter time, the vents also help to reduce fogging from your breath, again while riding a 2 wheel vehicle. As for full face vs not. Ask yourself this question, are you wearing the helmet because you are required to or because you want to protect your head. If it is for protection, why not make sure you get the benefit of the full face. It will help reduce the smack of an airbag on your face and also provide more protection if the steering wheel is pushed back into the path of the drivers head. But then, how much should you pay? I remember seeing an add for Bell helmets years ago, that said, got a $10 head, buy a $10 helmet. With Bell being a high priced helmet, it kinda made sense. But then I read a report from the CHP on helmets, and they found, it didn't really matter how much the helmet cost. If it was on your head during the accident, odds are you survived, if it wasn't, odds were you were dead. Their motorcycle accident reports show that head meeting concrete is quite often fatal, but protected head meeting concrete is not.
Oh, a special message to nsxtacy. In favor of Consumer Reports, when buying minivans, pay attention to which ones have the note that head-on collisions cause the steering wheel to move up and into the path of the driver's head. I think it was the Dodge Caravan years ago that had that special note.
See, I do read it and pay attention to what I find.
