Audio Systems: Ford Explorer Radio, fm transmitter kits, ford explorer sport trac

Question
I have a Ford Explorer Sport Trac (2001) with the 6 cd in dash changer (YL2f-18C815-GD).  I am wondering if there is a way to wire an axuillary input into this radio.  I have built a car PC and want to run the audio through the radio, but have had issues with the little FM transmitter kits with engione noise etc.  I think the best qualityw ould be to hard wire it in if it could be done.  Can it?  

Answer
I will not say anything cannot be done.
This would be better accomplished if you start with the PC 1st and go from there.
But I would run a Linux system with Mandrake OS on it [if you know how to run it].
Then you can interface to a few different types of decks.
It would not be wise to use the factory deck for many reasons if you are going to a PC.