[Steve Van Doorn]

said, "car “brains” are GIGO without security; the BIOS is wide-open" "Huh...could happen, right?"

Yes i believe it can be done. I've not looked into it enough to be positive about it.
I wouldn't buy a automatic steering car for parking or anything else.

[Cletus.D.Yokel]

Full disclosure, I believe it WAS done in the described Indiana case.

https://abcnews.go.com/US/driver-fatally-struck-siblings-school-bus-stop-found/story?id=66386083#:~:text=A%2024-year-old%20Indiana%20woman%20who%20struck%20four%20children,a%20light%20on%20issues%20of%20school%20bus%20safety.