Hi. i would like just through a few things into this debate.
in order to hide their entry into F1, VAG have been developing the F1 PU within LMP1 facility. they have been using a McLaren TAG-320 (F1 Standard ECU) to run their gearbox for the past couple of years and this gave them access to the unit without causing too many waves.
they have also built a new facility next to the LMP building and when i was out there last, it was evident what this new F1 Spec building was for.