a bad alignment will not make the car vibrate...it will only wear tires!!!!!! remeber that. there is no way possible that a out of alignment (only that) will make the car shake. if your vehicle is out of alignment...it is just that....it will wear the tires and nothing more.

check for bent rim..slipp belts in tires..bad front end parts....tie-rods, balljoints, cv axles, motor mounts and rack and pinion. my guess would be bent rim or slip belt in tire.

is it more of a wobble? do you feel it in the seat or see it in the steering wheel? any changes if you step on gas? or is this just cruising? if you wnat to know the answer...the answer all the question above.