Thanks... you just caught me before stepping out for the night.
The yellow harness is a airbag/seatbelt harness. Since it is unplugged it is likely something deleted on your vehicle (seat air bag delete for example). It is not relevant to our radio situation.
The black box is the amplifier for the radio.
The harness we would be looking for is the one indicated in the illustration I posted a few days ago... it would be in the front of the seat area, beneath the carpet... on LHD vehicles it would be on the left/driver seat side. Being under the carpet, loosening the seats is most likely to be necessary. The connector is a 24 pin connector of two rows, the top row has 5 pins, a gap, then 6 more pins. The bottom row 13 pins.
We need to find that harness, as it is most probable that it is unplugged or has been re-routed to a different harness (like I mentioned before for rear seat entertainment use). If we can not find it, then the only option would be to run new wiring.... specifically:
Radio pin 4-Brown ---> AUX pin 6 Black
Radio pin 13-Yellow ---> AUX pin 4 White
Radio pin 14 Orange ---> AUX pin 5 Blue
This is far from ideal though as you would need to incorporate some sort of shielding to prevent it from picking up interference (the factory wiring is shielded).