I think we all agree, the game has great physics. That means a lot for my style of playing since I despise the "arcade" style of physics that you get with most other driving sims.
Having said that, one area that needed addressing was gravity. The in game gravity was too low and the car was twitchy because of that. What I did was edit the .INI file on the line that referenced to "gravity"... increase that to 3.0 (if I remember right) and you now had a more realistic gravity and better corner grip!
Since I no longer have the game installed, I can't remember the details.