I also have done HVAC digital Climatronic mod and investigated adding real dual zone to my coupe. Never done it but given it some serious thought. Yes, you’ll need the linkage kit,… and any flaps they connect to! Problem is you’re only adding 2 more stepper motor for partial dual – should be 4 for fully dual zone since our coupe and C240 with single zone only has 6 stepper motor and fully loaded dual zone cars has 10 stepper motors. But the real pain is changing the wiring, the wires are connected in series so you will have to be able to access every single stepper motor which means tearing apart the entire dash. And then you’ll have to code it on MB STAR Diagnostic System. End of the day, better to just buy an entire under dash HVAC system and switch out your existing one then code on MB STAR. Either way, I don’t think it’s worth it. I’m happy just to be a digital Climatronic dual zone Poser!
Removing the radio centre console cage was a real pain,… literally, I almost dislocated my shoulder! It’s not just the two tabs in the back (attached to steel supports) that everyone is talking about that’s difficult,.. but plastic nipple at the front! This radio centre console black plastic cage is suspended in place like a vise! The 2 tabs in the back attached to steel supports hidden by foam but it’s the front part that’s hidden just behind the dash under the centre air vent that you must tackle! That dash piece look weak but it’s reinforced in the back with little shelves to hold the the radio centre console black plastic cage in place (see image in mirror in first photo). In the middle of that dash piece there’s a screw and to the right of that a little plastic nipple that locks the radio centre console cage dead centre. DRILL OUT this plastic nipple! Then it’ll allow the radio centre console cage to wiggle from side to side and there’s enough flex to just pull it down. You still need to deal with the two tabs in the back but now it’s a lot easier. When re-installing, the plastic nipple was drilled out with 1/4″,… so when re-installing put in a (rather low profile flat head) bolt and nut.