I have a new (to me) '08 RL, and when I was poking around in the trunk, i found the DVD player. Now my question is, what's the purpose of this if I don't have the Navigation system? Is it only for GPS function, or would I be able to pop a nav disk in and enjoy the ten+ yr-old nav system that never came with the car?

 

I think on base models, that dvd player is actually just a crippled navi unit that only shows a compass on the screen.