One problem related to brake light on has been reported for the 2006 Mercedes Benz Clk Class. The most recently reported issues are listed below.
Bought the car in oct. Of 2013. Third brake warning comes on from time to time. Have checked my brake lights with someone pushing the brake pedal while I observed more than once and they work fine. Two of my CO-workers have told me recently while following me that my third brake light does not always work. I know there is a brake light issue that is being recalled on a different mercedes model and year. Was thinking that my vehicle might have the same issue.