since no one has any ideas, they just fill up the board with stupid stuff. for the slower people, let me elaborate.
yes the rear end is non adjustable. so how did it get out of whack. it was in an accident, run over curbs, frame twisted, etc. since there is no adjustment, how else would it be out of alignment (not from mis-adjustment). this is all assuming the rear end really is out of spec, which i have no way of knowing.
so when something traumatic enough happens (ie. being rear ended), what do you think happens to the unibody and things attached to it? the force is absorbed by these components and they tend to bend and get out of spec. so a frame shop puts the car on a jig and straightens everything as much as possible. but it seldom goes back to original. so SHIMS are inserted in the frame and supporting structure to achieve the original geometry again.
what do you think a body shop does when your unibody tin-can gets hit and has to be put back together?