Rear clunking sound!. If it is not exhaust hangers loose, sometimes it could be the pitman-arms broken. Yes, broken. These "dogbones" are clearly visible visible from the near the front of the rear wheel underbody. It had two large nuts attached.
The pitman arm is basically an aluminum alloy piece about 4 inches long about 3/4 inch thick with holes and rubber bushing in each end.
I have seen 2 broken dogbones in the parts shop. I must say I was shocked!. I raced my 525 in the track for over a year and mine never broke. only the sway bars made the annoying noise as they rebound slowly to their original shape. Only a few mins after I do a cool down lap when parked.
So these pitman arms do break!. When the rubber bushes are worn, it could cause the rear of the car to wander in uneven surfaces when you drive fast or slowed into a turn off from the highway.