does the nav disc have to be in the dvd player for the nav to work or can you take it out after setting your route and play a DVD?

once u set your route it will keep it in memory so yes u can take it out and put in a music CD or the like. BUT if u need to change your route of anyting u need to put the navi cd back in.

bottom line get an Ipod, dump your movies and music on it and use the 200 cable to play your songs w/ the navi disk permantly in the unit

You can also set your "Home" area on the unit, and it will copy your home area's map info to memory, then you can drive around, and still have it map routes for you without the Nav disc in the drive. You can even play CD's or DVD's and it will still allow you to see detailed maps for your "Home" area. I'm in a pretty dense area, and it stores map data in memory for about a 20 mile radius.