Three problems related to wiring have been reported for the 2010 Mercedes Benz C300. The most recently reported issues are listed below.
Received message rear license light out. Replaced bulb but continued getting message. Rear parking camera started displaying images when brake depressed. Messages continued to check all rear light bulbs. When inspecting, I noticed burn marks on bulb carrier (part #211-545-03-28) and plug (part #204-820-09-77). I purchased new parts to install but had difficulty removing the wire clips from the plug. I was not aware and the mercedes parts department did not mention I would need to also get connector pins (or that this overheating was a recurring problem). Unable to easily remove wiring & pins, I decided to search internet for guidance on replacement (before cutting wires) and discovered several websites reciting others having similar problems with overheating of the ground wire connection and that a recall investigation had been started. It certainly appears that this problem of overheating/melting of parts is a real fire hazard that is occurring frequently enough to at least require that a notice be sent to car owners to have carriages & wiring promptly inspected and repaired.
Passenger taillight connector/wiring insufficiently designed for load. Wire/connector plastic is melting and causing unsafe conditions. This is a very common problem with 2008-2010 c-class and is frequently noted in mb owner's forums/websites.
Rear tail lights have progressively dimmed over time. Wiring harness was melting. Connector to light carrier and taillight wiring was corroded. Repair of corroded wiring, connector, and light carrier was required.