I have not been impressed with the base model stereo that came with my 05 Xterra S and have looked high & low for a double DIN unit. The RF unit needs too much work and I finally stumbled upon ths unit. It is non RF, but has the following upgrades, bass, mid & treble, Speed sensitive volume, 6 CD changer , MP3 as well as RDS, plus it sounds 200% better than the original OEM unit. I removed the two connectors & antenna plugged this new unit in, and 15 mins. later, I was in hog heaven. Here is the pic.
http://www.flickr.com/photos/46505540@N00/