"I also had a chance to take the RS4 on one of my favorite twisty roads in the rain and the effectiveness of Quattro working in a 420hp car with high-performance tires was very impressive. I was able to drive the wet road at speeds that I would never have even attempted in the BMW M3, and the ESP was still not intervening much. I even tried it in the rain with the ESP turned off and while it did slip around a little more, it never felt as if it was going to swap ends or slide off the road."
Full article:
http://www.theracesite.com/index.cfm...e&mag_id=12479