The first thing about doing it right is to make sure it has been developed in an appropriate manner for safety-critical systems, which includes, but is by no me

The first thing about doing it right is to make sure it has been developed in an appropriate manner for safety-critical systems, which includes, but is by no means limited to, adequate testing. The second thing is to require the owners to take some action as part of the installation procedure, so that it is hard for them to overlook the fact that it has happened. The third thing is that changes with safety implications should not be bundled with 'convenience/usability' upgrades (including those that are more of a convenience for the manufacturer than for the user.) To be fair, I am not aware of Tesla doing that, but it is a common enough practice in the software business to justify being mentioned. And it has to be done securely. Again, I am not aware of Tesla getting this wrong.