W210 ride quality. What to expect.

[guyever]

I replaced both the struts and accumulaters on the rear of my E320 about 3 months ago. I felt like that the ride improved considerably, but it still felt kind of "clunky" over a rough bump. The other night we were out and I had 2 adults in the rear seat and the ride improvement was dramatic. What I'm wondering is why such an improvement and how can this improvement be continued without the rear seat passengers (they have lives of their own and need to do something besides riding in the backseat of my car)? My son is in the auto business and had a mechanic at his shop do the replacement (not a MB mechanic). I wonder if the system was properly bled (I understand that the system is self bleeding and I did the weight in the rear, start the engine and let the car level again, check and refill the hydrolic reservior, etc). What else could be wrong? I bought this car 6 months ago and if it had not been for this web site I would have probably sold the car by now. You guys are great and I appreciate your help. TIA,
Guy