If you're worried about this you could always go to...oh can't believe I am going to type this...touchless carwash lol...DON'T FLAME FOR THAT LOL. It's just a suggestion though.
Has anyone ever taken vw up on this?
and if so, how bad does it have to be to get it fixed by them?
When I hear perforation, does that mean the rust has to burn a hole right through the panel before they will fix it??
I have some surface rust and they weren't willing to fix it..
I haven't read the details of the VW rust warranty but most manufacturers warranties are for rust through not for surface rust. It can take years to go from surface rust to rust-through.
The interesting thing about this car is that for all the bitching and moaning about little quality issues, the underside is, while not all that aerodynamic, quite cleanly done and dare I say beautiful. The engineers have chosen to spend there nickels where they count, not necessarily where you look. Even if undercoating were worthwhile, which it isnt, to properly treat the car would require tearing the whole thing apart. Put your car on a lift and take a look. You'll see what I mean. Its quite inspiring.