My partner has a nice 2nd gen Mini ONE from 2008 (it's got various extras but I'm not too hot on what they are yet but she's very proud of it

).
On Wednesday she went out to the car to drive home from work and found the steering lock off without the key in.
Then she tried to start the car and up came every warning light.
Once started the fuel range was giving random readings and the speedo didn't work and all the warning lights remained on.
She's taken it into Barons in Ash Vale (who always seem nice and helpful when I've been about).
They said initially that the diagnostics system said that every failure light was on (which she could see) however it couldn't pin point the fault.
They have tried again with the diagnostics system and this time it reports that the ECU modules appear to be talking to each other fine.
They suspected a chaffed wire on the car somewhere. They started manually checking the wiring but gave up after a number of hours.
They are now in discussions with BMW technical people as they say they should be able to diagnose the fault remotely with the diagnostics system.
She's is obviously very worried, I wondered if anyone had seen anything like this before or might know of any helpful questions to ask the people at Barons...ideally to limit what could become a massive bill