I have had 2 of these exact units. One in my Super Duty, and I currently have one in my Sti.
They are very nice, user-friendly units. You can change the color of all the lighting and the background to match your interior. Pretty farking cool.
They put out big power and have a separate subwoofer output which you can control from the touch-screen. There are inputs and outputs for monitors and/or backup cameras.
Requires an external receiver which you can mount in the glove box, and also need an antenna.
You can control audio AND Video ipod through the head unit. You need the proper cable for BOTH audio/video. They are about $40 on ebay.
Navi is pre-programmed into the unit and it will function quite well WITHOUT the disc. However, you need the disc to get full navi functions. There are 2 different discs, you have to use the one for your demographic. They sell for about $20 on ebay...
Very simple. E-brake wire gets grounded and looped to the main harness. This allows you to input navi directions, and watch movies/video while the vehicle is in motion. GOTTA HAVE IT!
This is an awesome deal. Original price on this unit was around $1000. They are several years old now and have been phased out by newer models. But I loved it so much in my SD, that I hunted for another one for months, to put in my Sti.
Hope this helps! Good luck with the sale!!