One problem related to brake light on has been reported for the 2013 BMW M5. The most recently reported issues are listed below.
The vehicle mentioned above caught on fire when I was driving home from work on a snowy evening. The trip to my house is around 7 miles and after about 6 miles, I parked along the street as I saw smoke coming from the vehicle and brake warning lights were being displayed. When I got out of the car, I saw a fire under the right rear wheel well. The car was totaled. Researching about fires in Bmws I found quiet a big number out there. Now we are worried to even drive the two other Bmws that I still own.