I have a 2005 cooper S 106k on it. Came home tonight and noticed the 3rd taillight is on and will not shut off. Anyone else ever hear of an issue like this? I am going to try and locate the fuse and at least get the light turned off tonight but obviously will need to get this sorted out for real tomorrow. Thanks for any help

 

Won't be any help to you but my 06 cabrio did that one night. I disconnected the light and then reconnected it a couple days later and all has been fine since..
Can;t explain that though..

 

I had that problem when my car was not starting, or it would start but the center taillight was on - wiper on - stereo dead - & headlights were dead. I cleaned up a bunch of electrical connectors behind the kick panels and under the dash and the problem went away.