Anybody Know what make system is fitted in the MY03? I would like to buy a CD changer for it.

Kenwood.

Any modern Kenwood disc changer will work, though I think there's only buttons to access the first 6 discs; 10 discs play, but I think you have to step through the last 4 discs tracks :D

According to the manual the radio presets do not select discs in the changer. The only disc changing functions are the ^ and v buttons. So hopefully you should be OK. Would be interested in the result because when I tried to ask Kenwood the same question they would not respond. Perhaps something to do with selling the 467 changer at a huge markup thru IM. Suggest you might be interested in the 719MP changer for as little as £200 which may allow you to play MP3 files from CD thru the OEM head unit. Hmmm ....10 CD's of MP3 files. Don't even think I have that much music.

Does the head unit have an aux input? I want to connect my MP3 jukebox but not use the cassette adapter as it keeps ejecting.

With regards the original head unit, I tried speaking to various people to determine what could be used, some said no problems in using any Kenwood changer, others said only the one available from Subaru (the chip in the head was such that standard Kenwood units woulnd't work) and the other option was as per top of thread. I also spoke to Subaru to find out if there were any RCA outputs, they took a few days to get back and tell there was not.
In short, I changed the head unit, once out, the original is very basic, no optional connections. So if you want to expand the system, a new head unit is required.

Chris

No aux input. Kenwood CA-1CX adaptor lead will work for you.

And, for the record, I plugged my Kenwood KDC-803 changer of some vintage into it; it works.