I also have a big "clonk" sound when changing gear from R to/from D (automatic) and the car moves slight even with my fot on the brake pedal. Would this indicate a bad flexible coupling?

Then I have this annoying loud sound coming from the rear at ~85km/h and ~145km/h. I can hear the same sound but much much lower all the time but at the given speeds it is really loud. Would this also indicate a bad (or two bad) couplings?

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Patrik Sjoblom....1993 MB 320 CE......Bought Jan 2001. Only 16.8 mpg
Stockholm.........Silvermetallic....DEFA immobilizer/alarm + Original larm
SWEDEN............17x7.5 ET35 wheels with 215/45-17 Kumho 712 ECSTA .