I'm getting a g35 coupe at the end of this month. I'm planning on buying one with just the stock navigation system installed. What exactly can this thing do besides be a navigation system? If I put a DVD movie in it will it play the movie? If I want to play movies will I need to buy a different unit? I have a portable video player that has A/V plugs (yellow, red, white) and I'm planning on having the car customized so I can plug this into the display. Will I be able to customize the stock navigation system so I can plug in an A/V cable to use the screen? Thanks for any info!