That's disappointing.
I just had my work van changed over (Toyota Hiace), & it's USB is both power/data. The tracks even appear on screen & you can navigate through the 'folders' on the iphone using the steering wheel controls....
VW need to catch up in this department. Music's a big thing & makes the whole driving experience complete for many. Easily accessing your music on any device should be standard on high-end vehicles like the GTI by now........