Happy to hear the positive outcome, @Kimmax! Hope you get to enjoy many miles of driving now!Alright, car is back home. First and second gear feel like never before - better than before. About the "taking the engine apart": Basically what @Porter said was done, so nothing to worry about.
Subwoofer has been fixed. KEF sounds good, but doesn't match Audi or Mercedes premium options IMO. For a factory built in it's pretty good. If I paid extra I'd think about that again. However, keep in mind that audio forever will be a hard discussion topic based on personal opinions
Complete Oil-Service set me back about 430€.
All-in a satisfying experience. Issues were fixed in 2 days. Had I delivered the car in the morning they might have been done next day. Road assistance worked great. If you get stuck on the road all you need is a bit of time and patience. You'll be taken care of all around.
Curious, did they provide a root cause for the issue? And/or warranty/assurance against it happening again? Not sure if that's feasible but just asking...
Now I do wonder if roadside assistance is only for overseas? In the US, I'm at least 3.5 hours from my deposited dealership. Not sure if they would retrieve it from that distance? And how I would go back to get it after it's fixed, perhaps ongoingly? Or how your situation would have turned out if you had been that far? ..