it's finally thrown an error on the throttle body apparently. The stealer is going to replace it. This a big job TT ?.
Well at least they found the fault now.

And as Topher states, is an easy job - in fact, so easy, it could be done in about 15-20 minutes. If you have ever lifted your big plastic engine cover - it virtually stares at you!
Have no faith in them or any other dealer doing it without breaking something else 
Sadly, that seems to be a common occurance. But if they do fcuk up, just make sure you let VW UK know - because they can actually take action against 'failing' stealers. But I've got fingers and toes crossed for you.

not great for a brand new car.
Agreed - but don't forget, the part that failed wasn't actually made by Volkswagen - and at least VW customers arn't 'beta testers' - like certain F0rds are!!!!