Yes Eddie it is the add-on unit. I did not run into any issues with harness wires being wrong, though I did have to purchase a different one because I have the older black colored "World" style plugs. I think that wiring issue was on the early version of this unit and cable, and the seller assured me they were not having issues with the harness. As far as effort to install it took me maybe 45 minutes to have it installed, in the dash, and up and running. Very easy!! I mounted the tuner just to the right of the head unit, the interface box on the left, and the cable just in the dash below the radio. I used some velcroe just to secure both pieces to keep them from rattling over bumps. There is a metal dash bracket that you can press the velcroe against on both sides of the head unit. Very easy!! I used the "Ford radio removal tools" to pull out the radio. I did not have to remove the surrounding bezel. Since you have the 6 disc unit it will be a plug and play, assuming you have plugs that are a grey color. Like I mentioned I have the older "World" plugs so I had to purchase a seperate cable to make the connections work. The antennae I mounted just above the windshield and I ran the wire under the rubber seal across the top of the windshield to the passenger side, then down the side of the windshield, through the gap between the fender and and door, then inside the truck and under the dash to the radio. I used some ties to secure the wire as it it runs just under and behind the glove box. Very pleased with the install!! And very pleased with the seller as they offered me a full refund when I discovered my truck had the "Wordl" style plugs and this xm unit and harness are designed for the "phase 2" plugs that your truck should have. The seperate harness I had to purchase actually come from a different vendor. Go for it Eddie. XM!!!! I havethis same unit in my wife's '04 Explorer with "audiofile" system and it was a plug and play install.
But this is a really good deal and if you have an "audiofile" system with the grey colored "phase 2" plugs then this kit is plug and play.
