So I am not sure what sound system is in the car but I recently got all Options printed.

Can someone tell me what is:
S694A CD-Wechsler Vorbereitung Provision for BMW 6 CD Changer?

Is that a prewire for in glove box DVD changer?

Since I have no DVD changer or player in the car (other then nav for maps only) how can I add it?
Also, there is not back entertainment center too.

Thank You all.