Put the powertrain lockout system on a signed and physically protected network segment. Let the headlights, mirrors, etc live on a less secure segment.
This will impose higher costs when replacing these systems, because it will require key management of some kind. Either central cert management (with 20 year expiry?) or local key management. So only impose this on a tiny subnet for the starter/immobilizer.
This will impose higher costs when replacing these systems, because it will require key management of some kind. Either central cert management (with 20 year expiry?) or local key management. So only impose this on a tiny subnet for the starter/immobilizer.