A couple of weeks ago the missus drove over some large sections of dry stone wall, that some inconsiderate lorry driver had pulled over in front of her. I had the wheels re-aligned (the NSF wheel was toeing out somewhat afterwards) and the car seemed to be OK. Now however, a rather serious shake has materialised under mild acceleration and the NSF wheel jitters and spins when accelerating hard out of left hand corners on less than smooth roads.
Being used to the previous sure-footedness of the car (94 Legacy turbo), I know there is something awry, the question is what?

 

Has the wheel been checked, could it be buckled from the impact?

 

Did you just get the tracking done or did you have a full geometry check? I suspect you may have done damage to other suspension components (and the front differential if the impact was BIG!).

Nigelward suggests a buckled wheel - try swapping it to the back!

If you find your brake pedal sinking further than it should then DON'T drive the car - I once went over a roadworks ramp at speed (it felt like a 3" kerb!) and thought nothing of it until a week later when the handling felt dodgy. When I jacked the car up the left front wheel just keeled over - the driveshaft had snapped in the hub with only the brake caliper holding it on!!!!!

skid.