Snapes 73' Dart Resto

Killing time today, looking at this ISIS system for rewiring my car. Know that I got my head around the idea, I like it. I think I am gonna go with that.
Would be kinda cool to have that modernization.
Rest of car is gonna be modified, why worry about keeping stocking looking/functioning electrical.

I was just talking to a friend of mine about the multiplexed systems. My worry is what happens if one of the modules fries out and the company is no longer in business? Are the different brands of multiplex systems proprietary or interchangeable?