Visiting from the e24 board: I had similar problems, replaced bushings etc. Much improved, replaced tires, put on Michelin Pilots, improved but still some shimmy at 30-45 mph. Had the wheels rebalanced, lasted a week. Finally took it back to Discount Tire and had them match the wheel to tire imbalances. They have a special name for it, but what they do is to position the tire on the wheel so the heavy part of teh tire is on the light side of the wheel. This requires a special machine, remounting tires and retest. I ended up having to tires remount twice each, and the shimmy went away. $40.00 charge. Good luck.