In which the COMAND wheel breaks

Well, I've driven quite a few miles recently. Mostly using the sat-nav. And then, suddenly, it stopped working. I was in a pub car park, in Kings Lynn, about to head the 276 miles back to home.

I'd selected "My Address" and just wanted to zoom out to check the route it would take me.

Nada. Nichts. Nothing.

I twisted the COMAND wheel and the zoom didn't work. Reboot the system. Still nothing.

A failure, probably in the hardware of the satnav.

I had to scroll the route manually and diagonally on its 0.5 miles zoom view to check that the car was providing a sensible route.

Back at base, I checked Dr Google. It showed the control wheel and the small plastic shaft that can break inside the unit. It costs £10 to machine a metal replacement. I considered a home repair, but decided that this would be one bridge too far. To dismantle the car's console, then to dismantle the spring-filled Controller unit. Then to replace the connections that interfaced to the telematics of the car, and the digital signals that operated most of the car's components.

There are too many things that can go wrong with this ostensibly simple repair.

The COMAND wheel was the heart of the control system.

Instead, take the car to the dealer. Practice not inhaling too sharply when I'm told how much the repair will cost. Think instead of the tens of thousands of miles I've driven under the control of COMAND.