I replaced my RSM's with OEM and a reinforcement place and then retightened almost every nut and bolt on the rear suspension. Clunk is gone. Not really sure what did it because I didn't test drive at each point, but I'm just glad it's gone.
I believe the shocks that were installed were Sachs? I could be mistaken. It was 11:30 last night when I got home from school and started doing this.