I have a 06 Murano S, it has the 7" Color LCD. I don't have Bose, Nav, or Sat radio. Is there a way to install Sat radio and/or an extra audio input from a portable DVD player.

Not sure how well it works but it seams like a pretty simple devise.

http://cgi.ebay.com/Nissan-Murano-NAV-TV-Video-Converter-WATCH-DVD-MOVIES_W0QQitemZ320066169479QQihZ011QQcategoryZ486 05QQcmdZViewItem

All Muranos after 2003 are prewired to the rear drivers side seat base for factory satellite. The parts you need are as follows;
XM Tuner Kit 999U9-AS003
SIRIUS Tuner Kit 999U9-AS004
XM Antenna Kit 999U9-VS000
SIRIUS Antenna Kit 999U9-VS001
Mounting Bracket Kit 999U9-CS000
This will run through your factory system. If you want to go another route look at PAC audio for audio converters (http://www.pac-audio.com/)