Adaptive cruise control engineering question

[ScrwLoose]

Can someone explain to me in simple terms why a Z 71 suburban cannot have the adaptive cruise control added to it? I've come at this ad, numerous angles, and the continuous response is that it has to be installed at the factory. In my head, the only reason something would need to be only installed at the factory, is if it needs to be welded onto the frame. if the vehicle has the radar and the cameras needed to run the system, it seems to me that it would simply be a reprogramming of the computer. Thanks in advance.
-mike

 

[zora]

Someone would have to spend a considerable amount of time looking up the part numbers of all the individual components, it's not a kit with everything in it.
A quick look shows something as basic as the switch on the steering wheel is different as well as the steering wheel.
Look it up at gmpartsdirect.com