Help and information wanted please! My Dec 2011 525d (218) has developed an electrical burning smell from the central armrest where the usb and aux connections and the Bluetooth adaptor are. Ive only noticed it over the past few days and only traced where it was coming from today. Nothing has been plugged in there since I updated the audio software over a year ago and that went smoothly. I tried updating the software via the usb port today and nothing happened. On the idrive screen under updating the software it said there was no usb device connected although there clearly was. Has anybody else come across this or had electrical problems in the center armrest.