1999 Discovery CD Autochanger Cartridge!!

Hey everyone. I need help if possible. No one else seems to be able to provide an answer for me.
I have a 1999 Land Rover Discovery (not a series 2).
I bought it used and love it, BUT...
The CD Autochanger that is housed under the passenger seat does not have a CD Magazine in it(you know, the cartridge that holds the cds inside the cd player). So I obviously can't load cds into the changer. I need to get my hands on a magazine for the CD Autochanger.
Can anyone help with directing me where I can go?
Any real help would be appreciated.

Thanks.

-Cam