Quote Originally Posted by RoyalSilver
Whoa! thats not good! If its so air tight then the car will be filled with carbon dioxide from your lungs and youll fall asleep and wreck. Happened with the old beetles, they could float too.
Well I was exaggerating a little bit but its not too far from the truth. You bring up a good point though.

Anytime I drive long distances I always put it on fresh air. And every hour or so I'll put 2 of the windows down all the way for a few seconds - just to get some change. It really helps you stay awake and aware, especially when its cold outside.