This problem started with a small bump sound from the rear and next day it got really bad. Had it checked out under the ramp from a friend at kwik fit to find oil running down the shock. Asked them for a quote and they said £375 + £25 fitting which i thought was expensive until i went to MB which quoted £744.50 + £200 fitting. 2hrs later kwik fit called to say they could not touch the car because of the airmatic system and would need to be done with Star Diagnostic so i felt at a kinda dead end and would have to pay the £944.50. I only saw one used shock on ebay for £250 and was tempted to buy it. My mate who is ex mercedes said why dont we fit it and then call on the AA/RAC to use their machine to correct the suspension if anything fails or drops at the rear.....Good Idea! but i have now opted out of this plan. Called another MB and they are doing it tomorrow for £450 supplied and fitted with 1 year warranty. The morrow of the story is that if this happens to you at some point you will have a better understanding how to deal with this situation. Also shop around!!!. Front ones are different again and cost £850 each. Starfall