what stormi said!
when i just got my drivers license my B4 would sometimes wiggle on the freeway. didnt happen often so i didnt bother looking for the problem.
some time later my rear bearings needed replacement, so i removed the rear wheel and saw the previous owner forgot to put the axle for the 3rd bearing in it.
so it actually only used 2 bearings instead of 3
after i made new one and put new bearings in it never wiggled again.