Comment by johschmitz
10 hours ago
The control messages are transmitted via CAN bus
https://en.wikipedia.org/wiki/CAN_bus
The exact message content and protocols are reverse engineered.
Some cars use FlexRay instead of CAN bus but that has only experimental support.
Flexray is supported only on Audi on a specific Flexray-canbus integration board that was just end of lifed and Comma has no desire to support other boards. It was a proof of concept for anyone wishing to implement the same