This is generally handled in one of three ways: * Filtering the OEM messages to prevent them from reaching their destinations, which can be accomplished if Com

This is generally handled in one of three ways: * Filtering the OEM messages to prevent them from reaching their destinations, which can be accomplished if Comma hardware is installed in the correct place in the bus to function as a two-ended "gateway" / "relay." Of course, then if the hardware or forwarding software fails, something else breaks... * Relying on the end-user disabling the OEM feature which could conflict with Comma, and signaling an error state if they do. * Relying on factory sequential integrity checking to overwrite factory messages by beating them in a timing race, causing the Comma messages to be "valid" and the factory messages "invalid" (no joke!). * Just "spamming" the message so it's received more often than the OEM ones. As you can tell, this is not a trustworthy safety product by any stretch of anyone's imagination.