Three problems related to brake light have been reported for the 2010 Mercedes Benz C300. The most recently reported issues are listed below.
The ground wire for the rear brake lights is heating up. Mercedes dealer fixed this, per NHTSA recall #14v-177 but the issue is reoccurring.
Warning light on my instrument cluster prompted "check left tail and brake light". I checked all the bulbs, they were all functioning except for 1 or two dim bulbs in the left taillight assembly. I unplugged the connector/harness to the assembly and found one of the wire insert connectors to be melted in the plastic connector, the melting affected the plastic as well. I am worried for a possible fire hazard in my trunk compartment. Contacted mercedes for a service appointment.
All of my exterior light bulbs have been replaced every other month. The rear driver side brake light burned out the metal part where mercedes had to replace the unit. As of Monday, April 2, 2012 I had to take my car in the dealer to repair a right front passenger side headlight out.