Ignition button and CANBUS system?

[Mattty]

Hello,

I've been thinking about wiring an ignition switch, such as this, into my Clio 172 Ph2 track car. I have a question about CANBUS systems, as I'm not entirely sure, even after reading up about them, what affect they can have when you try to add aftermarket modifications. What would be the complications of trying to wire in one of these switches into a CANBUS system and why are CANBUS systems harder to add things to?

Thanks!