I have a 2004 X5 4.4i with Navigation, CD stacker Bluetooth & TV

I am researching how to install a computer (Carputer) and I need to find the Radio module so I can connect the audio to the tape input, and I need to find the video module so I can connect the video out from my computer.

According to what I can see on here my Radio module should be mounted with my Nav unit, but I only have the DVD/Nav unit and CD stacker mounted there.

It also appears that my video module should be underneath my spare tyre, but there is a large metal dome, that looks to have air lines running to it (I assume air suspension compressor?)

Any suggestion son where to look would be appreciated.
Thanks
Andy