Dash cam hardwire.

[BarryH]

Canbus has been around for years,

To quote the opening paragraph of Wikipedia CAN bus is a "robust ... standard" Hal frauds had better wise up that ICE cars are going extinct like the Dinosaurs whose Fossil Juice they burn. :
"A Controller Area Network (CAN bus) is a robust vehicle bus standard designed to allow microcontrollers and devices to communicate with each other's applications without a host computer. It is a message-based protocol, designed originally for multiplex electrical wiring within automobiles to save on copper, but it can also be used in many other contexts. For each device, the data in a frame is transmitted sequentially but in such a way that if more than one device transmits at the same time, the highest priority device can continue while the others back off. "