You could have the portable portion hold some of the music collection and have the car dock be the master storage. You could remove/add playlists/songs on the portable on the fly depending on your mood/need.. It would be rather bulky though considering what's already stuffed into the empeg, but without the VFD you could gain some space.
_________________________
Dave Clark Georgetown, Texas MK2A 42Gb - AnoFace - Smoke Lens - Dead Tuner - Sirius Radio on AUX