Its obvious your satisfaction and enjoyment has declined of what truly ought to be inspiring.
Why not direct your query to the MB service centre. They might be the best people to see about your problem. We had our steering problem in the 260E rectified at no charge - despite it being out a few years from the showroom.
Thats the only kind of after-service we get around here - that is if we ASKED.
126 tailed by a 203, 129 leading the pack.