Here is the harness:
The decoder:
The extension that comes with the harness:
One last thing that SHOULD work is the rear camera should not require a backup/reverse wire because the harness pulls it from the factory wiring and gives it to the head unit. Still need to get power and ground at the rear of the car for the camera though. I'm using some generic cheap backup camera but they are all (including the Joying), pretty much the same.