You attribute a head gasket and differential leak to oil of any sort? How did synthetic in your crankase make your diferential leak.

Cause and effect is a funny thing. Just because you put in non-Mercedes anti-freeze does not mean that's the reason your sunroof or radio fails. And yes, one more vote for "your dealer is milking the warrantee".

First, your dealer has a gold mine with the Starmark warranty. They can make all of these repairs, get paid from MB and not have an unhappy customer on his hands...it is a win-win for everyone but Mercedes. I can't tell you how many times my cars go up for routine maintenance only to be told they found something wrong and have to order parts...then my work order has several under warranty repairs added to the "A" or "B" service. Last time they charged MB for a new windshield claiming they broke mine changing the windshield wiper blade! I looked closely and think they didn't change it...even the inspection sticker was intact and perfect from my local mechanic!!! I think these dealers sometimes run a scam on MB to run up big bills under warranty IMHO. Whether they will even do half of the things they charge them for is another story!