Whats needed to upgrade my nav unit to the DENSO unit?
 

Since it appears that Mazda is not going to provide an upgrade disc for the 2004 navteq unit, what would I need to upgrade to the Denso unit? Is it just the dvd player in the rear armrest or do I need to treplace the screen as well? Are all of the plugs the same? I also read that somebody was looking at a double din dvd player/nav reader, is that an option?