on E53 there are 4 tubular support things, one set aft of the rear wheel, the other set is rear of the rear wheel... when you look through the wheel well into those tubes, you will see that they are "filled" with bushing(s)... those are rubber bushings, and sometimes you can just see rubber crumbling out of the tubes, sometimes you see the rubber is half gone or otherwise being "sick"... before replacing them with OE bushings, check to see if PowerFlex makes bushings for your car...

That is for E53, not sure about your ride...