When i hit the cloverleafs to get on the highway and turn hard right it feels like the back end is running away from me, you cant help but correct it slightly which makes teh car seem to shimmy and wobble in the rear.
This is my 4ws 626. Good lower rear ball joints, wheel bearings, etc. Only thing left would be tie rods that i haven't replaced back there.
Do you have the center transfer shaft? I was driving around a 4ws with no center shaft for a while. I totally understand your @ss end running away from you feels like. I used to sway going like 70mph It was pretty messed up!