the steering wheel shakes (almost feels like flex in the front end) when going through a higher speed corner (repeatable on many corners) with anything but a perfect surface. the car is a '05 6mt sedan with 28k miles, stock. the wheels and tires I assume are in balance (had a good shop replace the tires recently, and come to think of it it was shaking before with the old tires and no wheels required large amounts of added weight). The steering wheel only shakes during high speed cornering, the car is smooth up to 130 ( I haven't taken it any faster but would assume it to be fine). I will lift the front end up this weekend and check for play in the ball-joints and wheel bearings but I am not hearing anything to suggest that. Any ideas?

as a reference point i have driven this back to back with my dad's BMW 5 and it is not exhibiting this.

 

Compression rod bushing could be it or the control arm has a sloppy bearing. Since your car is not shaking anything at high speed going straight I would point the blame at that. Just take a look at all the bushings.

 

Make sure all your lug nuts are torqued to 80 ft-lbs.

 

Thats where I would start. +1