The last time VW dealer advised to do OTA update was told (straight face, so presumably with all seriousness), pretty much word for word, ready: "you don't need to be driving the car, just turn on the ignition, don't start it but leave it outside, not in your garage so as to recieve a clear signal, for half an hour or so, ideally an hour to be certain, and it will automatically perform the update by itself". I'm sure it will, only, it's unlikely to still be there when I return or if it is I'd likely wish it wasn't....