Check your shocks for the manufacturer name stamped on the tube- (ie:Sachs, Bilstein.)
If they are Bilstein, no matter how old they are -they have a lifetime replacement warranty (with Bilstein- not Mercedes)
If they show signs of significant leaking, pull them out and send them to Bilstein requesting replacement under their warranty. Keep in mind that a small oily buildup on the shock tube is normal, and that is NOT covered.
You'll also have to find other transportation for the 1.5 week turn around time to get the replacements. I've done this a couple times on 2 Mercedes over the last 10 years with no problems.