Fitting factory reverse camera

Hi. I have fitted a MMCS to my outlander 2015 model. I had the basic audio system but thought I would try the MMCS. In the loom there were two extra plugs taped up, one was green for the GPS module. All I had to do is get a GPS sensor. Everything works fine, even the energy flow, which was a bonus. My car didn’t have the revere camera so I thought I would put one in. I bought a factory camera and cut the hole so it looks like s factory system. I have tried finding a proper wiring diagram for the reverse camera, but the wire colours are all different.
Taking the rear panels off there are various plugs, I think the left ones are there for the power tailgate, which my car doesn’t have. On the right there is a four pin plug with a shielded wire so I checked and all wires go to an eight pin grey plug on the back of the radio. when you unplug this plug, the radio switches off, so I assumed this is not the camera plug. I’ll enclose a picture of the rear of the unit. Does anyone know which plug and wires will go to the rear camera? As all the plugs are there from the MMCS I thought there may be a plug taped up on the rear to plug into. All I need is a decent wiring diagram. Sorry for the long post. Thanks