I need to know what the hang up for the installation of an AVIC Z2 in a 2004 VW Jetta GLI. It has the right amount of space height, width, and depth but for some reason crutchfield says it cant fit. Is it something to do with the wiring and if so, what exactly is it? Thank you all so much, Cam

It's because Crutchfield is wrong. They say no Double DIN headunit will fit because the opening in MKIV VWs doesn't have ISO mounting brackets.

You'll need the ADT-V133 adapter kit to install it, but it will fit with no problems.

Also, what all else do i need to make the installation perfect? And like I said thank you so much for the speedy answer skicrave!