Look in the manual and find out what types of file are accepted.All stereos should do mp3,but I use .wav (uncompressed) files for mine.Arrange your tunes into folders on your PC/Mac and then copy/paste to the USB stick.Plug stick in and select stereo to appropriate input and then select folder/artist/track as desired.That's how it works on my Mitsubishi Lancer,I presume it would be similar on a Passat