Thanks for the question. No, I don't carry anything particular heavy at the back. AND, most of the time I don't have passengers at the back! As to the "level" issue, if I look at the car at the side, it occurs to me that the back of the car is actually slightly higher than the front, if not level. So, I have ruled out that the "weight" is the cause of the problem.
HELP! ALL suggestions and probing questions are welcome!
1987 W124 300E Auto right-hand drive