The thing that gets removed is this:
http://www.dension.com/kepek/60.pict

Which is fortunately delivered as text/plain. Nice.

Anyway, the text on that unit claims amongst its features:

Stand-alone player features for home use

That's the only reference to actually using it for playback outside the head unit. If it was a portable player, they'd say do. Sounds to me like it'll require an external power supply and doesn't have a battery.