i dont know if i am asking too much, but is it at all possible, to run

sat navigation
DVD
through the one lcd screen...as well as using the same screen as your head unit. and wat features would the screen need (if it could be mp3 compatible as well)

 

You might get a better response if you asked this question in the "Electronics" forum.

 

But the answer is yes. There are a lot of ways to do it. I'm not sure if it is still available (new or used) but I think the Clarion AutoPC would do it.