I have done a search on this and have been getting conflicting opinions. Some say it is virtually impossible while others say the MFD, DVD under seat,, and steering wheel is the only things needed. I have a 2006 without navigation with MFD working well and a 2005 with navigation in full working order. Can someone with definitive information help me? Thanks.
the 2006 nav system was different than the '05; you might run into problems because of that. might need to change the whole interior wiring harness, or it might not even be possible. sorry I can't be definitive, but I've never seen anyone do it.
It's been done before on an 06. it's quite a bit of stuff but if you have the whole car available that's another story altogether. Of note is that they use the old MFD as a proof-of-concept. This suggests that the base model MFD has a composite output; something that's never been proven before. there's a blogspot au post by damntechnology, back in September 2009 covering the installation. Should be easier in your case since you're going to swap out the head unit as well.