Cockpit view is stupid.
It's like looking out a window that's inside another window.
It won't serve its purpose unless it's done with the use of Oculus Rift.
Cockpit view mimics what we see in both peripheral and foveal. Peripheral = steering wheel, dashboard, speedometers, etc. Foveal = road ahead you.
The problem is, as we're playing the game, our peripheral is the TV and every area surrounding it. And that makes our foveal vision look at the "cockpit cam", which is again like looking through a window that's inside a window.
I never understood this thing at all. Having a cockpit view doesn't make it any more immersive than it already is, save the wiper-rain-snow thingy.
Using logic to claim it doesn't add to the subjective element that is immersion isn't going to work.
What's immersive to you doesn't necessarily equal what it is to others and vice versa.
And unless GT is played on a multi screen and fully working mechanical simulator the whole experience is not only always going to be artificial (even on that simulator) but it mostly offers an illusion of reality at most.
So using bumper cam and perceiving my TV screen as the windscreen doesn't work for me to get the most immersive feeling the game can offer, nor do I feel it's the more realistic experience even though logic might suggest it.
I simply can't trick my mind to that perception as much as you might not get over the perception of seeing through a window that's inside another window.
Your feeling of immersion or realism might be based on strictly reasoning what's ahead of you and adjusting it accordingly so that it resembles the real situation as close as possible, factually, that's a very literal approach.
I don't analyze it that way, knowing full well I'm playing a videogame I use the view that most resembles sitting inside a car (that's cockpit view for me) with all the extra visual elements/info (and limitations) that to me adds to the immersion, by which I mean experiencing another key characteristic of that car (and not just any car, visually, like the generic bumper cam does) whilst driving.
Ofcourse it isn't accurate nor realistic but neither is noticing a table, cupboard or potplants being in your peripheral vision whilst driving a car.
Maybe it's simply noticing the 'extra fluff' that cockpit view provides that gives an extra distraction from the actual peripheral stuff in my house, so not a window within a window, but an extra layer of artificial nonsense that tricks my brain into perceiving (or imagining) more reality and makes me focus better on the road ahead strangely enough.
It works for me so I perhaps shouldn't analyze it anyway, even though logically it might be considered stupid.