I have two questions:

If I have the trunk-mounted 6 disc changer and I want to install the mediabridge in the trunk, do I lose the use of the disc changer?

Would the kits be the same for a 2000 E39 M5 w/ Nav and a 2003 X5? I currently drive the M5 and would like to buy the mediabridge now but will be switching over to the X5 within a year. If I could move the mediabridge with me when the time came that would be great.