Suspension issues, but what are they?

[bobthebuilder]

My 2004 9-5 Arc has nearly 200K miles. I bought it at 192K and did some serious engine work to get it going. So I'm driving daily now, and have some suspension issues I'm having trouble identifying. When I hit a bump in the road, especially on a curve, I can hear clunking in the rear of the car, and the entire rear end feels like it is shifting in the outward direction of the curve. I don't have to be going very fast for it to do this - 20mph will do it. At faster speeds it feels very unstable. I'm sure there are a few worn out parts back there, but I know very little about suspensions and how to diagnose them. I would appreciate suggestions on where to start looking? Or should I have one of the local tire joints/wrenches put it on a rack and give me a diagnosis? I prefer to do the work myself if possible. I don't have a press or a lift, just more time than money, jack stands and a garage full of most mechanic hand tools known to man. Thanks guys.

[CaptainMediocre]

How do the springs and dampers look in the back, any fluid leaking out the dampers? Any dry rot on the various bushings and bits back there? On a 10 year old car with serious miles, I am willing to bet the dampers and springs could stand for an update.

[Finding41]

You need new shocks. May as well get the whole strut as our cars are known to have saggy springs.

[bobthebuilder]

I hit a big pothole on a left turn tonight with the RR tire and thought the whole back end of the car was going to fall off. Huge clunk and shudder/shift. I am going to put the rear on jack stands this weekend and see if I can see anything - leaks, bad bushings, etc...