S320 Problems
 

I have a 2000 S320. I have owned it for 6 years and have spent a fortune on its upkeep both cosmetically (valeted once a week) and mechanically (MB dealership service). It has now just turned 100,000 miles. However, in the last few months the bottom of all 4 doors have started to rust and more importantly, in the last week or so the car has picked up a shaking at around 70-100mph. I have had the wheels balanced but that did not help. A friend said it may be the prop (or a part of the prop) or it could be wheel bearings, although this is unlikely as there is no noise. The doors I have sorted. MB had huge zinc dipping problems between 1999 and 2003 so this is a common fault. MB said they would repair the rust if it is rusting from the inside out and they would not help if it was rusting from the outside in.....needless to say they insist it is the latter so they have told be to get lost.

I could really do with some help on the shaking please.

Also, I seem to get a slight time lag (split second) when flooring the throttle and then there is a slight 'clunk' noise and a 'thud' and then away we go. Could this be linked to the above problem.

Finally, I floored the throttle the other day and and got very little response and the engine seemed to have no power and would not change up.

HELP PLEASE