Hello people.
So I've got an Astra H (Mk. 5) GTC, it's 2006, sadly rather low spec, aside from the half-leather seats nothing much really. It even lacks an REC unit.

Since me getting the car I've retrofitted some components, with the most recent being a GID info display, and since the more capable BC found in cars with GID fitted, I would also appreciate Steering Wheel Controls - since I like how do they function in the other Mk 5 that we own.

But to be quite honest, I've got no idea on how to do this, other than needing to buy the physical switches with their respective cables.

I assume that the SWC is reaching the EHU trough canbus, thus the SWCs are connected into a CIM unit.
Are there some compatibility issues regarding CIM modules? Anything that I need to check before even thinking of spending money on a set of switches?