One problem related to headlight switch has been reported for the 2010 Mercedes Benz C300. The most recently reported issues are listed below.
Approximately once every 2 months while parked with the engine off, the front passenger side headlight will come on with the rear passenger side parking/brake light. When this occurs, I have to turn the headlight switch on then back off, to turn off the lights. On one occasion, I observed the passenger side headlight and the rear passenger light flickering like a strobe light, before I turned the switch on then off.