It's called "Eyes that tell a story" and that story is that this passenger is seriously freaked out about how fast her driver is going.
I normally get tired of girl-in-the-passenger-seat videos because the bikini babe freakouts in them are so often totally staged.
This kind of shock you can't fake.
(Hat tip to Brian via Arbroath.blogspot.com!)
This Hilarious Autocross Video Is Like A Live-Action Anime