Like the title says...found out today that my rear differential needs to be replaced after only having my car since the end of August 2017.

Everything Ng had been great until a couple weeks ago when Calgary went into deep freeze mode. On the way back home, I noticed a bit of a hum coming from the rear of the car whenever I would let off the gas at any speed. Thought maybe just the transmission was cold cause it had been parked outside in -30c weather for a few hours and the gauges were all showing sub-30c temps on the oil and trannny.
Fast forward a while and the air warms up, car temps come up like normal...but still getting the sound.

Called my my dealership for an appointment this morning and received the news a few hours later. Apparently even the foreman went out for a rip and gave the same prognosis. What makes me wonder is that they have said that it’s still okay to drive...um what!?! I of course asked what would happen if it decided to self detonate while I was doing 100-ish on the highway...but didn’t really get a great answer that fills me with the warm and fuzzies...

Is there a actual Mercedes Rep, not a dealer tech, that I can call and discuss with?