Guys, this looks like a serious Q5 and A4 issue. There is a sh*t storm going on at the German Audi Forum at
http://www.motor-talk.de/forum/unwuc...-t2360258.html about that topic.
People experiencing steering wheel shudder and vibrations from 100-120km/h (60 - 75mph) after roughly 3000 miles. They had their dealers change tires, balance the wheels on the car, changed suspension arms and the brake disks - which fixed it for a while - before the same problem showed again after 2800 miles.
As of Oct 7 2009 it turned out that
IS the break disks! They distort due to thermal stress. The distortion then causes the shudder @ a specific speed. After replacing the disks it works for another 3000 miles before you need to start over again...
For Audi this MUST be a known issue and they need to come up with long term solution. That might be different disks or a whole new (larger) break system for the Q5 and A5.