I've just uploaded a "controllers dead zone demo". Did you problem got solved?
Tested... the problem persist. BTW I noticed that the steer input is digital, not analog! In that case the right deadzone value is 40%. So, actually, is perfectly playable via Xpadder.
PS: I'm praying for the sideview cam, no need to make it a fullscreen fixed size, but neither too close.... oh pleaseee :3