Yeah but it really shouldn’t be that way. Just add a pin or something, it’s way too easy for people to just grab devices or install malware to leak keys. The current standard for security is that everything is encrypted at rest regardless of whole disk encryption.

Signal is still better that most of the stuff out there but it’s not above well intentioned criticism

Intrinsically/semantically no but the expectation is that the texts are encrypted at rest and the keys are password and/or tpm+biometric protected. That’s just how this works at this point. Also that’s the government standard for literally everything from handheld devices to satellites (yes, actually).

At this point one of the most likely threat vectors is someone just taking your shit. Things like border crossings, rubber stamped search warrants, cops raid your house because your roommate pissed them off, protests, needing to go home from work near a protest, on and on.

RF analysis is kinda difficult, you’d need to take the car out into the middle of nowhere and have access to fairly good equipment. A tinySA would maybe work if you’re very patient but data transmissions are generally very bursty so it may be difficult to nail down where it’s coming from in a sane amount of time.

One option would be to try to figure out if there are any FCC filings for your car. All filings will have pictures of whatever module is being used and what antenna systems it uses which may give you a good idea of where it is and what it looks like. There should be an FCC ID mentioned somewhere at the beginning or end of the cars manual. Googling that should bring up some stuff.