I am all in favor of safety-critical software being open source, but I dislike the argument of forcing the issue by claiming the right to tinker, or really any

I am all in favor of safety-critical software being open source, but I dislike the argument of forcing the issue by claiming the right to tinker, or really any variation on "I bought it therefore I can do whatever I want to with it". It's not true when the hardware in question has safety implications. For example, when I buy a car, I do not have a right to do anything I want to with it. I can't drive it in ways that would be dangerous to others, and the fact that I am legally restricted as to where and how I may drive it does not feel like an inalienable right being taken away from me. That's clearly a strawman but bear with me. In a similar vein, if I were to physically modify the engine in such a way as to make it faster but fail environmental or safety regulations, that could also have financial or legal repercussions for me (or Volkswagen, to cite a recent example :). The same argument could be made against modifying automotive software- vehicles are certified by government agencies around the world based on the idea that they will perform a certain way WRT safety and emissions, therefore software behavior has to be just as unchanging and predictable as hardware behavior. The fact that people can and do hack their cars all the time doesn't change the regulatory environment for car companies. I do believe that embedded software should be as open, modifiable, and testable as possible, but I don't think people claiming the right to tinker as a basic human right are going to change anyone's minds about this. The biggest impediments to (for example) car companies making their ECUs open source and hackable have nothing to do with a dogmatic attachment to proprietary software and security-through-obscurity (although those concepts have their adherents, misguided as they may be), and much more to do with compliance with government regulations and minimizing their potential liability. There is at least a perception that having open source, hackable ECU software would be all downside with no upside to the companies selling those vehicles. The way to change this perception is to show it as being demonstrably wrong, rather than to simply claim a right to tinker. The best way to get open source ECUs is to either make the consumer market care about this (not likely) or to update the regulatory environment in such a way that car companies have a non-abstract motivation to go open source. This is not unlike the dreaded binary blobs required to use certain 802.11 chips on open source operating systems- they exist because of FCC requirements, not because the vendors love binary blobs. They are allowed to ship software-defined radios, but the only way they can guarantee that their SDRs don't broadcast on illegal frequencies is to lock down the software that controls the hardware. It's not an ideal solution, but its the only solution they've got aside from spending even more money to ensure that safety at the hardware level, which wouldn't do anyone any good.