OK, so got the car back, privacy mode not turned on. Car not contactable from the PCC centre.Service chap said to call Vodafone, but if it's a h/w fault, then it'll be yet another visit to OPC.
Look on the positive side......at least the lack of contact with the car is not due to it being in a container on its way to the far east.
Funny you should say that.
When I went to collect the car, the service chap gave me the keys and said "it's outside, in the covered bay."
Went outside. No car. At least, not mine.
Went back in: "My car's not there" to the look of some worried faces.
Turns out it was in the gated compound. Phew!
Porsche East London service not very joined up at the moment, it seems.