Alas I cant really help you much further. The game for me is just too far down the path of the console port to hold my enthusiasm for it.. Wheels feel very much an add on after the fact.
Pure conjecture on my part but The polling rate (in game ) of the USB control device does seem somewhat lower so the wheel may well not being fed the input it desires.
Have you tried running the game with the wheel in "game mode" ?
That may well dumb down the wheel enough to hold off the feeling you have. ( like the older WRC titles) You will have to reconfigure the wheel in game as it is technically seen as a another USB wheel.
Good luck