Guys - I own a 2001 5301 with Sport Package wheels. The car has been great since I bought it in the summer of 2001. I am experiencing a shimming/vibration problem while I drive. I thought originally that it was a tire problem. I installed new tires (Micheling Sport A/S). The problem surfaces at any time, low speeds and high speeds. When the shimming kicks in, braking magnifies the vibration. When it happens and I slow down it feels that one of the tires has a bubble as it "hops". If I stop the car completely and wait a couple of minutes, the problem goes away and the car rides very smoothly. Could this be a bearing, ball joint, tension arm or something else? Advice is greatly appreciated.