Any idea why you can't look around the car while in cockpit view? Not all around the car but I seem to recall PGR 3 not allowing you to look behind you with the right analog stick if you were in cockpit view. You actually had to use the rear view mirror.
I may be mistaken but there was a fairly recent game, and it featured mostly real cars (it wasn't GT5, remember playing this well before that came out) that allowed you a limited range of motion within the cockpit to look at the mirrors, down a bit near the radio, up (for whatever reason) and off to the right. In Forza it just gives you a view to the left, right, and back as if you're viewing a camera attached to the outside of the car.