Signed software does not equal blackbox. You can still verify that the software in the vehicle is the same as the provided one (download the software from the vehicle and compare checksums for example).

Again, there must be software parts that must pass homologation to be allowed to run on public roads. The same is true for a lot of things, your laptop for example has lots of firmware blocks that you are not allowed to change because of regulations (emc and emi for example).

And that is a good thing. Trust me, you don’t want untested software on the street, risking lives. That’s why vehicle testing is done first on closed roads.

Ah, but this is a different discussion. You want to be able to run modified software in a vehicle.

Then the question becomes an architectural one. Which Software components do you actually want to modify and still be street legal? In theory a modular structure can be build where all homologation and safety relevant limits are fixed and monitor the other non critical components. These non critical components could be changed without needing new homologation (you know, like „apps“).

You could also make the other ones modifiable with the limitation of losing street legality. So you could only run it on closed tracks or private land. Just like manufacturers do today.

This is the same like for closed source. A new software release must be tested and have regression tests that homologation relevant parts are not changed and if they are changed, that they do not violate regulations.

That’s also one of the reasons why the software has different components. So that you can update the hmi for example without affecting the steering function.

Going down further that road, there are very specific regulations that cover software updates in particular. There needs to be a software update Management process behind it that makes sure software is only distributed to vehicles that it is designed for.

But none of that would be more difficult with open source…

Again, we are not talking about a crowd built vehicle, there still needs to be a manufacturer behind it.

This is only the infotainment. This has nothing to do with the rest of the car

Mm not really. The TÜV does not have a problem with open source.

But you need a manufacturer and a company that stands behind it.

But open source car does not equal diy car.