Update: As stated before, re-balancing the wheels has reduced the steering wheel vibration by 80-90%. However, I am still experiencing some through-the-seat vibrations. The vibration is noticeable starting at about 30mph. It increases in frequency with speed but is a little more tolerable at highway speeds. Since I don't have access to a lift or regular access to ramps or a jack, I'll probably have my local independent mechanic try to diagnose it. My guesses are either the old runflat tires are just beat up and out of shape, or it is a giubo, driveshaft bearing or rear drive axle issue.
BMW CCA member - Peachtree Chapter
Last edited by LeMansteve; 10-10-2012 at 08:19 AM.