One problem related to brake light on has been reported for the 1999 Mercedes Benz SLK. The most recently reported issues are listed below.
This is in regards to recall number 05v505 for the driver side rear brake light. This recall occurred in 2006 and the light was fixed. However, it has failed again and has the exact same problem, the socked has gotten hot and melted/deformed the plastic socket. I don't know if the bulb was replaced only but to me it appears nothing has been done to repair this issue on this car.