Well, I put shocks all around today and gave it a good looking over. The spring perches looked fine as well as the rubber/plastic disks at the top of the springs. The shock mount points, etc. looked good too... No worn trailing arm bushings either.
It must be the trunk spring or the coils "settling" after the rear is jacked up. I had jacked it up to check the brakes and rotors after I got it and it's been up a few times.
Oh yea, the shocks were Chinese "Sensens". I read some favorable reviews on some forums but I'll say don't bother
One of mine has an ill fitting "donut" at the bottom of one of the front shocks (Where it bolts to the lower control arm) and it clunks
I noticed it before installing it figuring it would be OK...
It had the original MB shocks and one of the fronts was bad. The rest seemed OK with just bench testing.