First of all safety does not exist in a vacuum. And second, software is just a technology. If you have the tools you will be able to hack the device. What will

First of all safety does not exist in a vacuum. And second, software is just a technology. If you have the tools you will be able to hack the device. What will happen instead is, the car's software will be signed and even if you somehow get the sources, you won't be able to run a different version. Just like in tivo. Getting back to technology, 20 years ago you were able to hack the car with a wrench. Now it's just plain impossible to know what's going on. Hopefully not for too long.