As we learned from Polyphony Digital’s website, you’ll be able to use this head tracking technology to manipulate the “cockpit camera” and presumably look through the corners and at your opponents with the simple turn of your head. From the translation (confirmed by Yamauchi):

“…the movement of Cockpit Camera interface (confirmed in full 3-D. The camera can be fully manipulated and you can opt to have your head tracked by the PSEye)”