[BinaryIdiot]

> If a hobbyist were to modify something incorrectly and cause a malfunction of the car which in turn injured another, or damaged property, who is liable?

The hobbyist. Why would anyone else be liable for something a person did that then failed and caused harm?

> Insurance companies are going to fight it, maintaining that unauthorized changes were made which would release their liability.

The insurance company covers the car so you'd have to consult what their terms are in regards to modifications as plenty of people modify their cars today just not the software. I can't imagine a software change would be radically different to a hardware change in the insurance's eyes unless it's something incredible like an autopilot.

[baobabaobab]

>The hobbyist. Why would anyone else be liable for something a person did that then failed and caused harm?

The hobbyist isn't the one with money. The manufacturer will be sued, and they usually settle because there is probably something they could have done that would have made the failure less likely, injury trials are bad press, and jury sympathy is always on the injured little guy's side.

This is how it plays out with physical products, I don't see why it would be any different with code.

[Qwertious]

That's not what happens if a hobbyist modifies e.g. the brakes, then the brakes break and the car crashes - if you modified the thing, you're responsible for the issues your modifications cause.