Hi,
There's a thread working on this on mp3car.com forums -
http://www.mp3car.com/vbulletin/showthread.php?p=711704#post711704 . Please note however that you will "only" have a digital input, not an analog aux-in as the changer is in SPDIF. For analog connection, connects2.com offers a working (not cheap) solution which includes both an analog/digital converter and a changer emulator.

Vicne.