In looking at another post, I saw a 560sel owner talk about noise in the rear suspension. On my 85 380se I recently noticed a noise as well. Under acceleration, there is a knocking sound on the right rear of the car. After a few seconds, it goes away and it doesn't always happen. It doesn't sound like anything is rubbing, and I have the standard size wheels and tires. This is with no people in the backseat. Any ideas?