I hope this isn't a repost... If it is, please lock it.
If you go into the Forza 3 setup menu and turn on multi-screen, it gives you the option of changing the angle. If you increase the angle to something like 65 or 75 degrees, suddenly you are farther back from the wheel, you can see quite a bit more of the cockpit, more of your arms, and you can often see the entire side mirror. You can also see quite a bit more out of the side of your window.
Here's why I find this really, really interesting. There are more polygons to render when doing this and the game doesn't take a performance hit that I can see. That means there is "some left in the tank" so to speak... How much, who knows, but definitely some processing power that isn't being used.