No Bose hating please - I used to install commercial Bose systems, and my car has Bose factory audio with an extra 12" so I'm partial to Bose.
Anyway, the CDRW is for sharing data at meets. The black panel under the Bose emblem covers the floppy cage which now houses the Carnetix 1260.
Here you can see the layout. The Opus 150 powers the MB, HDD, PCI, Video and the Carnetix 1260/PW-70A powers the screen, USB hub, case fans, and USB DVD drive.
Video is a Ti4600, PCI holds Audigy, PCMCIA adapter with 200mW 802.11b, and a USB 2.0 dedicated to the dash USB DVD. All other USB devices are on the on-board controller and the D-Link hub.
Rear view shows the Opus and Carnetix inputs. The Opus startup/shutdown controller is used and the Carnetix is just a slave.
The red and yellow pairs are +12 and +5 outputs from the PW-70A to the external devices.