I think ultimately it comes down to human emotions. You feelz bad cause you fooked up your car. You're staring at $$$$$$$$ falling out your pockets all over the floor and you can't fathom it. Your rage of your fook up puts you into an emotion that you don't want to take blame for it and say, VW is going to fix my mess because it's under warranty!
You go to them and they're like, "Yeah sorry buddy, we couldn't get access to your crank shafts with that extra large intake in the way. Oh and the bigger turbo was pushing against the engine which didn't give us much room to work with. I know you have only 20k miles on the car and it's 2 years old, but um, I don't believe we sell the cars with those things in them." Then you're going to say, yeah well, how do you know my phat intake and extra wide turbo didn't cause my engine to blow? Do you think the dealer tech is going to stand there and give you a part by part break down of what happened? 99% of the time, probably not... They're going to say, you modified it to the point that it well exceeds what you bought and they can't determine what happened but again, the car isn't what they sold you.
I imagine, if all this talk and you just had bolt-ons with no tune, if you removed the parts and put back to stock, you'd have a 99.9% time of getting any of that warranty work done. The part where you have bolt-ons and a tune is where they're like, yeah buddy, go somewhere else, weren't not touching that with a 10ft pole.
My own real world story is I blew my turbo on mk6 at only 33k miles but had just gotten out of 3yrs. The dealer looked at it, sure as hell knew I wasn't stock (apr stg2 with all supporting mods). They flat out told me, now is a good time to upgrade your turbo because it's cheaper buying a new k04 than it would be a VW new k03... I ended up taking their advice since the car was just about paid off...
