If the Passat's Monsoon is anything at all like the Jetta's, you can get a cable from Blitzsafe that fakes out the CD changer input for any RCA component. Someone else did that one the board here, and I plan to do it myself (if I keep my Jetta... lots of electrical problems!). The cable is around US$80 and is usually a special order. Check on forums.vwvortex.com and search on Blitzsafe or mp3 in the Car Audio section.