They do disclose it, it’s part of the paperwork when you purchase the vehicle.

https://support.toyota.com/s/article/Toyota-Insurance?language=en_US

Of course the dealers make it very easy to “opt-in” by accident.

The fact that it’s out in the open, literally on the car manufacturer sites, but people still deny this behavior, is a grim omen.

They sell driving habits and other informatics to insurance companies at the very least, this is publicly known.

Hiding? Modern vehicles straight up have cell modems and advertise it, look up Toyota Connected Services for example.

When the cost to ship trash code trends toward zero, then there will not be value in shipping trash code. Companies will need to focus on software that is actually competitive (in a qualitative way) because otherwise their customers will just self-vend the slop code.