Hope to help others out there configuring their Logitech G27 for Dirt Rally 2. I found the default settings to require way too much arm strength to keep it from auto-correcting, and it didn't give any real feed-back for the road surface.
I just spent the whole weekend playing with the settings. I finally found a setup that works for Front, Rear and 4 Wheel Drive cars.
I have calibrated these specifically on the Australian roads, because that is what I know well.
Please see the attached images for settings.
Hope I can save others some wasted time. 🙂