Mitchell I had the same type of clunk coming from the right rear of my '95 E320. I would jack the car up and could not make it do it. Finally without the car jacked up I grabbed the link that connects the anti-sway bar to the suspension arm and shook it real good and I was able to duplicate the clunk. I removed the link and could see where the steel bushing inside the rubber bushing had been rubbing pretty hard against the bolt that holds it in place at the suspension arm end. I tried to center the steel bushing and then sprayed it with WD40 and now the clunk is gone. I will probably just replace the link/bushings if the clunk comes back. I did not see where the clunking was hurting anything - it was just aggrevating.
'95 E320, 87,xxx miles
'97 Honda CR-V, 66,xxx miles