[GH85Carrera]

The real answer to the OP is no one yet knows.

There will indeed be a lawsuit filed when it happens. We all know that someday a drunk will get in the car at the bar, and program it to take them home, and fall asleep in the back seat, or as the OP said some parent will put their kid in a car and have it take them to school and them come back empty.

When some driverless car kills someone, and the family sues Tesla, or whatever maker, no one at all goes to jail, just a big payday, and media circus.

Someday when full automation arrives, and there are no user controls, few people will even own a car of their own. Just tap an app on the phone, and a car arrives, and takes you to where you need to go. Like Uber or Lyft with no humans.

Most of the public ones will get defiled quickly, and the operating service will hopefully have an entire staff to clean the interiors.

There will be a premium level service of upscale cars and only people with "gold" or "platinum" service will pay for that level of comfort and cleanliness. I hope that is available by the time I decide to stop driving because I no longer feel like I can drive safely. I have several decades before that point I hope.