I'm hoping this comment is a joke? It's kind of nonsensical.

> I wish other car makers were as reasonable as Honda here.

I doubt they did this on purpose.

> No "evil valet" with half a brain cell would waste time hacking the head unit if they have physical access to the car.

Keep in mind that head units usually also contain historic data; stuff like left-over synced phone contacts in SQLite databases, historic location data collected either explicitly for telemetry or accidentally in log files etc.

Additionally, head units usually have access to a lot of internal buses in a car; depending on manufacturer there's sometimes some level of firewalling effort, for example through a Gateway module, but these firewalls are usually quite weak when they are present at all (see: the famous thing with Honda unlock and starter release working with no cryptographic material through the same CAN bus as the headlights). This means that the infotainment can usually control some part of the car, and is much more powerful than a tracking device.

Plus, implanting code (or just extracting the data that's already there) from a head unit leaves much less evidence than adding an additional tracker.

> Not to mention that people with Civics are never targets of three letter agencies.

???