Jambo, what is the goal that has been set for this game? What do you want to create?
For example... What is the target audience? arcade, driving sim, simcade, sim racing, pro-sim?
Also from what I can see in the videos. You need to drastically reduce the lateral grip on the NSX as it is too much like a 4WD now. Also slightly reduce lateral and increase longtitudinal grip on the RX8.
As for audio, try to hook up the tyre skidding sound with the grip level of the tyre. It feels at random and canned now, which doesn't really aid in audio feedback to the brain.
ps. This is just from watching the videos. Will try it out after some more coffee.
Edit:
Who's the one responsible for steering wheel support?! My T500 is handled like a gamepad. The steering is horrible this way and totally unresponsive. Makes it totally useless as it's practically dead around center.
Not to speak about the force feedback. Please at the very least let the centering force fade out when starting to drive, as in a real car.