If not Toyota, then who? Which auto manufacturers do it right? And is there any public evidence to support that? If not, then I'm probably just as "safe" or "unsafe" in any other brand of car as in a Toyota.
This is mere speculation but the software in Tesla cars is probably at least decent since they dared reuse some of the technology on the Spacex Dragon V2 capsule.
I think this is one field in desperate need of open sourcing. Anyone who has the capability and the desire should be able to audit the software. Modifications should be prevented by signing, unless the user signs that he assumes full legal responsibility for the effects of the modifications and has the vehicle recertified as roadworthy.
Open sourcing it is nice and all from an idealist standpoint, but given the complexity of the software (millions of LOC), the fact that all the software would be used in commercial companies, and simply the area itself (cars), do you really think the community would pick up on it? I doubt it. Plus, the researcher did audit it - 18-20 months' work, and that was just analyzing it, not actually improving or fixing it.
Plus there is no car manufacturer ever that would allow anyone to change the firmware on their own.
If not Toyota, then who? Which auto manufacturers do it right? And is there any public evidence to support that? If not, then I'm probably just as "safe" or "unsafe" in any other brand of car as in a Toyota.