Hi there, I've been hunting for info on this satnav/combo as well. In my case, I'm looking for a way to hack in an aux-in into the factory stereo to get an iPod working. FM transmitters don't seem to work with the stereo, which I believe are due to the shielding + the use of a band expander.
I've got a 2004 Outback with the TV/SatNav/DVD etc from Panasonic, but no SatNav discs. One thing I found interesting on mine is that the speaker (single) for the satnav sits just above the front passenger footwell, and is not integrated into the stereo. Is that the same on yours?
Oh, and in regards to Rapid Radio, I was deeply unimpressed with their sales guys. Went in there, had to almost beg to speak to someone about some audio upgrades in an earlier car. Got such crappy treatment I went to another place.
EDIT: The factory stereo is a GX201JE (Kenwood, I believe). Unfortunately both pieces of equipment are not connected in any way.