In DiRT 3 if you race with steering wheel and have trouble setting up properly, you may want to have a look at the settings for some of the top steering wheels below to assist you in setting up your wheel.
Fanatec Steering Wheel Settings for DiRT3
Logitech G25 & G27 Settings for DiRT 3
I hope this helps you guys. You can try these settings with your wheel for smoother and precise handling.