[dsx724]

The X1 is pretty high off the ground and small changes in air pressure and wind direction can cause significant torque to transfer to the base of the steering column from the body and wheels.

The problem you are noticing is due to the EPS implementation. Hydraulic steering constantly applies pressure where as BMW's implementation of electric power steering in the X1 is purely torque reactive. The EPS motor is reading the torque on the column via light beams passing through slits and then apply countering torque to the column. The reaction is pretty slow (50-150ms due to DAC and motor inductance) and you notice it.

Hydraulic steering act as torque shock absorber that will mask small changes in torque while transmitting large ones. This is the "feel" that people talk about. EPS can be designed to completely mimic hydraulic steering although you usually need sensors on the axle and tuning while making it a more costly and complex setup. With EPS, it becomes an issue of sensor location and signal processing to create any kind of feedback "feel" that you want. The technology is superior to hydraulic steering while individual implementations may not be.

Whether the car is planted or not is a function of the airflow, engine, weight, sprung and unsprung weight, and grip. What you feel through the steering wheel has little relevance in terms of the actual performance of the car. To get a good EPS system, you need electrical, systems, or computer engineers which are not typically found in the auto industry.