F10 5 Series - How to repair the 12v cigarette lighter fuse
The Definitive DIY Guide - How to Repair the 12 Volt Cigarette Lighter Fuse
You have put your car key in the central console, as design. However, like 99% of all people, you have other (metallic) keys attached to your car key. Sooner or later one of these will make involuntary contact with the open cigarette lighter contact. And then the fuse blows....clearly a design error in an otherwise very fine car. Now you have the resource to fix the fuse!
A big thanks to Ivan for putting this together for the community!