1993 740i sounds like somethings loose

My 740i has 195,000 it runs great. About six months ago I started hearing noise coming from the rear. first thought something was bouncing around in the trunk. Then i thought the exhaust was banging around. Both not true. So I got under the car looking for something loose. Man everything was as tight as could be. The noise got louder and more frequent to the point if I run over a pebbel I hear the after shock. Finally I noticed on both sides of the rear there are these two bushings . the passenger side has a support bracket attached to one of the bushings. the bolts that hold these bushing are tight and the bushing look fine , but there not fine . there is all kinds of play going on here as I am going down the road. It dosnt affect the handeling or preformance but man is it loud and frequent. How do I fix this because it looks ok just not working right ?