It is done, I am free!!!
I know there are people who can perfectly live with classic manual AC control, I knew that was not me but then when buying this car I convinced myself that I could and it turns out I really can't.
So in case someone else finds themselves in this position here are the details. Unfortunately MB went a bit more Spartan on R172 basic AC hardware which means more parts are needed compared to R171.
Hardware (Cars are not prewired and wiring is not included in this list)
A1729004504 – Automatic Control Unit
A2118300272 – Air Temperature Sensor (Improves blower adjustment response time)
A1638300272 – Temperature Sensor for Right Legroom (Improves blower adjustment response time)
A0175450826 – Legroom Temperature Sensor Connector Bushing
A2049057501 – Sun Sensor (Enables blower variation with sun level)
*A2229051300 – Pollutant Sensor (Enables automatic recirculation when pollutant level detected)
*A1728300114 – Pollutant Sensor Bracket
*A2205400681 – Pollutant Sensor Connector Bushing
*A0039900251 – Mounting Nut for Pollutant Sensor Bracket
*A1728300203 – Dual Zone Heater Housing (Enables different temperature between left and right side)
*A1648202042 – Right Heat Blend Stepper Motor (Enables different temperature between left and right side)
*I am not fitting the pollutant sensor because it is too slow to actually help and not fitting the new heater housing because that requires dashboard removal.
HVAC172 – RT_Einzeladressierung_Start 2C to 2A
HU45 – VCD_HU_Parameter HVAC Variant to 2-Zone (If you have COMAND)
BTW I previously tried the w204 automatic control unit, you can read about it here: https://www.slkworld.com/general-mod...ml#post3448762