I have 20K mi on a previously perfect C300.Approximately 150 miles ago a "wheel bearing" noise started coming from the front (right?) of the car at speeds between 54-59 mph.The noise is speed dependent.Shifting into neutral,down shifting or increasing the RPMs in neutral does not change the volume or pitch of the noise which can be heard with the radio off and fan on low.I installed my snow tires about 1000 mi ago(Michelin Xice) and thay show no cupping or featheredgeing.The dealer mechanics said it sounded a bit like a X-fer case bearing.He put the car on a rack and with a stethoscope tested all the possible areas and could find nothing.His diagnosis was the snow tires which sounds bogus to me.I suppose I could put on my oem wheels/tires but that's a pain in our "lovely" weather here.On the plus side they did do an electrical service campaign...Is this the dreaded X-fer case/transmission issue?