There are several people on the forums with various iPod integration methods.

Some use Harmon Kardon's Drive-n-play, some use other means.

I've installed a six disc CD changer (Becker make) and spliced into that with a Becker iPod adapter. The iPod adapter doesn't work with the factory head unit, but you can use the audio inputs with the CD changer hooked up.

Do a search on the forums for 'iPod' you will find quite a bit of information.

Cheers!