I called VW in December and asked. I had bought it on the 26th of November. They said that I would get BOTH. I was told by the dealer I would only get the guitar and that they were not giving out the fasts anymore. Both of them showed up, within about a week of each other.
This just goes to back up my impression that you need to go to the company itself to find anything out, NOT the dealer. :

The dealer didn't even know how I was supposed to get the guitar! They said 'just wait a couple months and if you don't hear anything, call VW.'
We ended up with the white one and it looks pretty nice. My husband (who plays constantly) said it is nice looking, but the quality just isn't there. Its meant more for looks than playing.
...and yes, we did play it through the speakers of the car. ;D