V60 Dual-Zone to Tri-Zone Climate Control: Adding Rear Seat Air Vents?

[IMAY2023]

So you can install  2 sensors under left seat, and 2 sensors under right seat, to read the same temp. I don't exactly how is at V60, but i've changed CCM module at  XC90, and XC60 who had some problems and i managed to do it without remove the dash. The module has only one clip that hold it, doesn't have screws or something. To make more room, you can remove the airbag and the right upper air duct (has 2 bolt)

No, it's not that simple because sensors are at least of the problem. The major problem is the missing dumpers, CCM freaks out because of the missing dumpers and it messes up the whole air vents. Air flow settings becomes useless,  vents for the windshield does not work at all. 

Anyway, I doing something else completely. 
The way the climate control operates is quite different on new VOLVOs. 
You have the center screen, rear climate control (either heated rear seats button or digital one with FAN speed), IHU and CCM.
Center screen and the rear climate control are connected to IHU via LIN. (IHU is the LIN master) 
IHU is connected to CEM, VCM via FlexRay. 
CCM is connected to CEM via CAN BUS (low speed 125kbps). 
Logic says program a button that sends LIN command to IHU to turn on the rear seat vent. But there is a catch, LIN master (IHU) would not respond to a LIN slave ID (the controller)  if it's not been initiated by the master. Even if you send the correct command syntax somehow, MASTER would drop it. 

So, what I am trying to do is this. 
Listening the Low CAN bus while the car is in 4 zone mode, turning on the rear seat ventilation from the IHU, capturing the command sent to CCM to turn on the rear seat ventilation. Then replicating the same command from a the sniffer device while the car in two zone climate mode. 
In theory that should work.  I already tested on the bench and I can capture the CAN communication and replicate the commands. 
The next step is listening the CCM what it has to say :-)