Wheel Related Problems of the 2002 BMW Z4

Wheel problem

But bought with less than 12,500 miles, they found turned unstable situation, has been unable to find what the reason, at times almost a major accident when driving, the tire does not feel sticky, but on the highway, the car is all over the place (like a drunk driver), the steering feels very loose, not too sensitive. If I do anything more than a slight rotation, dynamic stability control system has been started, if the curve went to the right, I had to "jerk" to go straight to rectify the same, if it went. When a straight road, it will feel very sticky, moving wheels. This is very scary, because it can not be diverted at any time, I will leave the road and down miles of canyon creek. This situation will not occur at low speeds. Unfortunately, I have a lot of problems with my 2003 BMW Z4 steering wheel. This is completely unstable. For example: 1) to maintain pull to the left or right. It requires constant adjustment, so that I can keep the car aligned or center. 2) I met a sudden twitch to the left or right when the road contempt imbalances. I can never predict the road the car pulled me. I struggled for many centers to stop at any red lights keep turning. 3) sometimes, the steering feels like being stuck. 4) I believe that if elderly people trying to drive this car, such a problem, there will be a catastrophic collapse. This is mainly because the driver must be a lot of attention to keep the car centered fact. Otherwise, any second, you might find yourself somewhere off the road, or under a truck. 5) I've been reading on the internet, many Z4 owners have encountered similar problems, I do.