Rear end squeaking when I encounter the slightest bump

What is your question?

I have a 1998 S500 1,300,000 miles. I maintain the car on a regular basis. This problem is located in the rear suspension. A disturbing squeaking sound occurs when I turn or just going over small bumps in the road. With the vehicle turned off and parked, I am able to re-produce the sound by pushing up and down on the right & left rear of the vehicle, it sounds like it is coming from both sides. Nor when I physically actuate the up and down motion, the car does not bounce up and down when I drive it. So I doesn't feel like the shocks are bad. I also had both rear bladders replaced last year., at that time the mmechanic said the shocks were fine.