Scottyboy is right-on here. Just look for any Fusion model that has a rooftop antenna. ALL 2007 Job 2 vehicles have rooftop antennas and the audio input jack. It's a 1/8" jack, exactly the same style as the headphone jack on an iPod (except for the new iPod shuffle, of course).
This works great. I've been listening primarily to my iPod while driving. Sounds better than the radio... The owner's manual says to adjust the music device's volume up until the sound level matches what you hear on the radio input. For my 4th gen. black and white iPod, I found that this means turning the iPod volume all the way up.