reversing camera
 

I own an Χ5 3.0SD 2009 and i decided to install the reversing camera part number 66 21 0 417 969.
I am trying to install it but as i see in the instruction manual an extra part is requested for the installation but it is not included in the retrofit kit which is mentioned as AVM.
Could someone help me by telling me if this part is already installed or do i have to buy it separately?
Thanks