Rear suspension noise

Son has a 97 gran prix, and whenever he goes over a bump you can hear a clanging noise in the back. Suspension seems ok, it appears to only be a noise problem. Any suggestions, and if cause is known, is it a fairly easy repair job?

Does he hav stuff in the trunk that would be rattleing/bumping?
Sometimes the jack and spare tire are not tightend down and they'll clunk aorund.

check rear sway bar links by grabbing the sway bar at several points and try to move it to mimic the sound. also could be rear strut mounts at the top of the rear struts just bring it in to your local independant alignment shop i bet its a strut mount and u need a spring compressor for that i bet they will do it pretty resonable

I had the same problem, a clunking noise that progressively just got worse. It turned out to be a sway bar link. The replacement units I purchased were easy to install, two nuts/bolts each, and the new unit has grease fittings. The replacements were also about twice the diameter of the originals. Not an expensive repair, the parts were only about $20 for each side.