A Gran Turismo game with real team management. You build and expand your own work site with wind tunnels, factories etc. There you can also build your own test track, gather sponsors, decide the team colors, logo and outfits, hire personnel, look for second drivers/test drivers and so on. Racing is determined not only by your driving skill but also by the team that you have put together. If you hire less functional personnel it might hurt your on-track strategies, if you bring the wrong kind of drivers it might hurt the morale, and if you decide to go cheap on car parts it might cost you reliability. The point is to give the player a much more complex reward/risk experience where your bond with your entire team and want to bring success not only to yourself but also everyone involved in the effort. Imagine going into the pit-lane and you know the name of all the mechanics chancing your wheels, because you hired them personally. And the reason that they pulled off a new personal best is because you have worked towards a good team spirit where everyone is happy and has great synergy.
I know this video game will never happen because it's so ambitious, but I refuse to let go of the dream!