03 P71 rear bounces BAD around bumps in corners

Just bought a 03 P71. Feels tite no rattles but something is going on wt the rear of the car. If i hit a bump in a corner the whole back end jumps into a slide to the point that i have to correct it wt the steering wheel. I'm going to jack it up and have a look and see if anything is going on. It just feels like the car has no springs and its mounted solid to the frame. You guys have any idea what could be going on?

I have a similer problem with my p71, I found a couple worn bushings in my control arms. I am currently waiting on some new arms from ADTR, going with performance arms because the rubber bushings on the stock arms are pretty sloppy even when new.