Try holding down the on off button and keep it held down for several minutes. That worked on a Fiat I hired years ago when all else failed to switch the radio off.

I'll try that. Not ideal, but if it works at least the radio is off.

Radio not responding?

The car is all computer driven.

If you had a computer that did not respond you would re-boot it.

Disconnect the battery, wait 5 minutes & reconnect - maybe a shot in the dark, but you never know.

That did occur to me. Does that reset the key codes, or are they stored in persistent memory? I suspect the latter. Yes, it also occurred to me that they try to drive as much as possible from one computer system to reduce costs, and as a software engineer, I know what they can lead to. I suspect these are niggles that will be worked out with future firmware updates. Hi Ho.

I bet it would also reset all the engine compnents back to factory specs, e.g. the settings gleened by the MAF etc, so the car would run rough until it re-learned how to run smoothly again.

Interesting. The dealer recently disconnected the battery and reset the system whilst investigating a wiper failure. That means that the car would subsequently have been running sub-optimally, and would have needed need to relearn. How long would it take to relearn? Are we talking about one 30 mile journey, or several hundred miles?