I like to drive without the cockpit view. Maybe its that I don't have a giant screen HDTV, but I feel like there isn't enough road for me to really get a sense of whats going on.. When you are driving a real car, you can of course see the interior of the car, but your eyes focus on the road and surroundings. I think on what we have seen so far, the cockpit view is too cluttered. In everything sense GT3 (my first GT game) I have just driven with the view that has nothing but the HUD.
I like qualifying in GT3 where it showed you your overall position in relation to the other cars. It was up in the corner and not very ditravting. I would like to see the option to add and remove various options concerning the HUD (map, split, tire wear, etc.). I think TCS, ASM, VCD, Brake Balance, etc. should be adjustable if not mid race, then during pit stops. lots of cars today come with the option to turn off TCS on the go. Speaking of TCS, it might be cool if cars that weren't originally sold with TCS didn't have it. Also, I think you should be able to make driver assists 'off' as the default.
I would like for there to be a test drive option when buying cars, as well as a new value depreciation system (there is already a thread on that, so I won't go into it).
I would like an in-race save feature for long races and enduros. They could program it in such a way that you couldn't use it as a, 'oh shucks I saved on lap 37, and wrecked on 40, so I will just reload, or maybe turn off my PS3 and then reload...' option.
Thats all I can think of now. But Im sure there will be more.