i've already ordered this unit for my Xterra, but I haven't gotten it yet. There seems to be some confusion. Here's what sjgreatdeals.com says about the unit:

-Comes with a 3-position switch between 2 auxiliary inputs & the factory slave unit
-In order to work, slave unit must continuously be playing or XM Satellite Radio® or DVD, must be on

So is their website wrong, or what? Just curious.