S500 Audio & Navigation

Just purchased a '06 S500 - No CD Changer in the trunk. What is the cd changer that works with this vehicle. Also, It seems like the Nav System lacks vibrant colors when displaying direction - kinda bland. Is there a way to update the Nav software? If so, what is the latest version available? Thanks for your help.

I could be wrong but your cd changer should be located on left hand side in your trunk under the lift up trunk mat. And as for your nav display you shoul be able to make contrast ajustments through your screen controls.
hope this helps in some way.