Hi ! That’s weird that your connector is different, I thought that all Peugeot 207 had the same RD4 audio unit.
Here are the schematics for the confort bus:
There seems to be only two confort CAN bus connections on the BSI: one that goes to all the car entertainment system and dashboard, and one to the optional rear park assist computer.
The green wires are the confort bus lines. They go to the BSI to connectors 40V BA (pins 28 and 30) and 10V NR (pins 10 and 8). You can see where those connectors are located on the BSI below:
Those are big connectors, I think it’d be difficult to connect your Arduino on them. You might have better luck trying to connect on the peripherals instead (such as the monochrome display). Keep hacking !! 😃