Went to dealer to collect USB stick. They had left it on one side for me as the guy dealing with this was on holiday (which I knew).
Plugged USB drive in to car and started the update process whilst driving home. Appeared to complete properly. When at home, I rechecked the versions which I believe were the same as before.
I rechecked the connected update…
It still thinks there is an update available. But of course, once you try and log in from the car…
Updating this post with the benefit of hindsight, I see that before the update was attempted, the vehicle didn’t have a date filled in for ‘last map update’. I don’t have the imtermediate screen grab, but as a later post will show, the ‘last map update’ field is now populated.