As well as the stuff I mentioned initially, I'd like to see a story mode that had cinematics, perhaps speech options, like you see in The Journey and Mass Effect, with multiple choices that take you down different story threads, and it would need to have top quality voice acting and motion capture.
As others mentioned I think it would bring the whole thing alive if you could actually develop rivalries, real rivalries, with drivers.
So if you took Hamilton out at turn one he would come up to you after the race and speak to you.
You get stars from other sports doing motion capture, FIFA being the best example, so why not f1?
I think it would add a lot to the overall experience.
After all, if you think about it the actual drivers are all mute, and could easily be robots for all the human interaction we have.
That, for me, is the priority as far as immersion and really bringing the F1 world alive in the game.
It's not 1997, things have changed in the gaming medium.
It is considered art in many places and has proven it can offer the player a rich, emotional, and complex, world with believable characters.
When we play f1 we have to play out any rivalry, any driver interaction, in our heads.
Again, many games have introduced real world sporting stars into their games, principally the E.A games, and so there is no excuse for such a global brand as f1 to be behind the times.
Aside from a brief podium celebration, which are all the same regardless of who wins, and some token shots on the grid pre race start, there is no relationship with the other drivers and that is a wasted opportunity.
I must add that I've found the A.I to be very aggressive at Monaco. (Apologies for not knowing every corners correct name...I know them all, just not sure of their order).
They will attempt a run up the inside of the first corner, if that fails they will follow and even try to squeeze through going up the hill and into the fast(ish) left hander before Casino square.
In fact, looking back over the many races I've done at Monaco, I can only think of one, maybe two, corners where they DON'T attack and try to pass...the many times they have ended up with them t- boning me or turning across me.
The corner they rarely attacked at being the left hander after the tunnel chicane and before the swimming pool left-right.
They also seemed cautious taking the penultimate hairpin corner (Rascasse), perhaps because of the cramped nature of the exit?
Sounds like Alonso is still driving the first race of season 1, no upgrades added, terrible on the straights version of the McLaren while you have developed the car through upgrades and are noticing significant improvements.
Surely if he were in the same, better version, of the McLaren, and that's assuming R&D is shared between drivers, he'd be qualifying further up?
It seems, to me, that it is one of two things;
1) R&D upgrades aren't shared between teammates and so he's stuck in the pre-upgrade car.
2) He is actually performing well/normally, relative to his equipment, and you are exceeding expectations and over performing by some margin.