The FCW implementation is completely open source, and can be found here: https://github.com/commaai/openpilot/blob/devel/selfdrive/controls/lib/planner.py#L78
The FCW implementation is completely open source, and can be found here: https://github.com/commaai/openpilot/blob/devel/selfdrive/controls/lib/planner.py#L78