How do I use my Zune on my Kenwood KDC-MP342U?

I recently purchased a "Kenwood KDC-MP342U WMA/MP3 CD Receiver with Satellite/HD Radio/Bluetooth Ready Front Panel USB/AUX Input" stereo for my car, and hooked it up, its great, love it. BUT It says that my zune is 'NA Device'. Is there a way to use my non-ipod mp3 player by way of the USB frontside?