[Christien]

From what I understand, it's more about what your eyes see coming at you not being in sync with what your brain feels. This explains why as a driver you don't get sick, whereas being a passenger you do, all other things being equal. When you're driving (particularly at the track or autocross) your eyes are watching everything happening, and your brain (and therefore hands and feet) are responding to that and controlling the motions as reaction. As a passenger, it's the opposite - your brain is reacting to what your eyes see, which isn't necessarily in sync with what the driver's doing.

I've occasionally got motion sickness at the track - very mild, but always concerns me because I'm very prone to nausea. I've found it helps significantly to look even further down the road.

Along the same lines, have you ever wondered how figure skaters can spin countless times and not get dizzy? It's the same thing - brain feeling something different than eyes see. From what I'm told, they keep their visual focus on one particular spot.