Thanks. I had also read something that I had to go find again.
Success!
Car Hacker's Handbook by OpenGarages
Car Hacker's Handbook
I'll have to do a side-by-side comparison. The Handbook is oriented to doing penetration testing on your own vehicle (white hat stuff). It at v0.x at this point, lots of stubs.
I presume that the Electric Vehicle conversion I'm not making progress on will use CAN Bus. From watching EVTV I take it that rolling your own, you can have multiple CAN Buses; one for infotainment and another for the mission critical stuff.