There's still a few things I want to accomplish before the tune.
HPA Dog bone w/ puck
Complete exhaust 3"
Lighter wheels w/ better tires
Intercooler (not sure on this one.. WA state is pretty cool and I won't be taking my GTI to the track, needed?)
Dogbone mount feels great, I'm sure the HPA interlocking one feels even better. Highly recommend especially for Manual.
I recommend the Intercooler as well, especially since you said you'll be getting a tune. And while it isn't California/Texas hot, WA still gets hot during summer. And as carchrism5 said, you'll see benefits on any weather.
You'll probably be fine without it if you're still on stock tune but you should highly consider it when you do get tuned.