sounds VERY similar to what i had on my right rear.after exhaustive investigations i/we found it to be the bushing that the bottom bolt to subframe area.it seems the rubber inside the bushing dried up and becomes noisy.an easy(?) and cheap way to fix this would be to remove old bushing and press in new one.as yet i have been unable to locate someone to do it.the alternative is to replace shock($$) and so i'm not giving up on the first option.as i say this was what i found with my car,let me know how you make out
