I will never understand this mindset that the dealership owes you something because your car had an issue... That's what a warranty is for. I understand it can be unnerving when a new car has issues, but let's be honest, these cars are mass produced and no one has a perfect record of zero manufacturing mistakes. If the vehicle is fixed and no other issue arises that is related, why does the dealership or VW owe you anything more? The car had an issue and they fixed it. Hopefully they provided you with a free rental(covered under warranty for any repair that requires keeping your car for more than 1 day) and didn't inconvenience you significantly. An engine replacement isn't minor, but it sounds like they are taking care of it without any hassle... Parts that are not available in the states take time to get here.
I work at a dealership, so maybe my view is skewed, but I've never felt a shop or dealership owed me any more than fixing my car as promise. Being a pain in the ass customer that always acts like we owe you something is not the way to get us to help you. Why would we want to go out of our way and spend extra effort helping you if we are met with an attitude like that? It will quickly make you the customer that no one wants to work with and that no one is willing to go the extra mile to help... I suppose the The wheel that squeaks the loudest is the one that gets the grease, but just wait and see how long that works for you...
Sorry for the rant, but I see this attitude all too often. /rant