Ok, so I know I said no mods until after my base tank, buuut the mod bug got me. While I had the headlights off the car to re-clear them, I discovered the Jetta has a cold air intake from the factory. And no, not the "cold air intake" we all put on our cars when we were 16. This is a proper snorkel that goes from the airbox to behind the drivers side headlight to draw cooler air from the outside. I went ahead and removed it since its best accessed with the headlight out. Now its breathing nice warm engine bay air, and I know plenty of others here have proven gains from warm air intakes.
Besides that, theres a mesh screen inside it that was completely clogged with dirt and debris.
I also discovered that the upper grille feeds at most MAYBE two inches of the radiator and core support, so I think I'm safe to do an upper grille block, at least in the winter.
Pics are attached.
Oh, and if anyones interested, I can do a quick writeup on refinishing cloudy headlights here, or on whatever subforum is appropriate.