agreed if it changes under accel/brake then i would also suspect that the control arm bushings are worn. What happens is the inner part of the rear bushing pulls out and separates form the outer rubber part. the control arm can now pivot and will vary your steering angle and give you weird handling, mostly understeer (plowing feel on turns)
im sorry i dont have a before pic but heres what it looks like with the Energy Suspension Poly Bushings in the front control arms. The rear bushing is of a totally different design and will not fail as easily as the stock ones.
