Co-pilot vanished up its arse trying to download a map update and of course Google maps won't do anything without data even if it knows the destination (home) and patently has the maps already cached locally.
That's why I have TomTom installed. Not only creates that total independence of any network connectivity (unless I want to enable traffic updates), it also stops Google from getting my location.
Win win :)
Biting the hand that feeds IT
