Got to see all the lights on the dashboard come on one after another, in the following order, whilst driving from Canterbury to Deal.... battery charge light > Rear Air Suspension Light (both) > Three Amigos > SRS Airbag > S+M. Then they all went off at once, which was a relief, until I realised the temp gauge, fuel gauge, tachometer and speedo had all gone off too..... but that was OK as a moment later the engine stopped. And then nothing worked, except my AA App on the iPhone. Top AA Man out, and confirmed my fear that the alternator had fried itself. The tests showed a 95amp leak to earth from what remained of the cooked battery via the alternator.
Fair play though, he disconnected the alternator and made cables safe, and dropped in a new charged battery so we could drive to a garage and pick up a loan car as I had to get stuff done today. So looks like I'm in the hole for a new alternator....... but on the upside, doesn't appear to have zapped anything else in the process!