I thought of this long time ago, and I'm sure many people thought of this too so sorry it was posted before.
My idea is that the driver should use his hand to change the gears. On the F08 and FXR just shifters on the wheel like a F1. On the GTR cars just sequental so the driver just pulls the stick to shift up and pushes it up to shift down.
it matters by the enigine revs, when you're not moving and holding the gas so it revs, lets say 7000RPM it does waste gas, press F12 and see what happens
they should do it, and when your car flips you just wait. I know this is going to take a long long time to make but they should make so one (or more people) person drive a towing truck and tows the car to the pit. but i'm not sure if that would work well..