I bought my c300 4matic not to long ago at the Mercedes dealership now I am noticing a noise coming from inside the cabin while the car is driving. When the car is stop I dont hear it. The noise is a whining or humming that in coming from the center or rear when I open my window while driving I cannot hear it but I can hear in within the cab. I look some research on the web and it has me narrow it down to a transmission problem, but my car drives smooth and shifts fine there is just a noise. I booked and appointment and the earliest they can get me in is Tuesday. I'm hoping it is not a transmission problem but if it is will Mercedes cover it cause I did buy it from them as a certified pre-owned and I've put less then 2000km on it since I bought it 2 months ago.