You need to actually read the links you’re providing.

The buyer’s remorse one specifically refers to high-pressure sales such as door-to-door salesmen or a temporary business location (meeting a salesman in a hotel), or some subscriptions or delayed services. Nothing that would apply to buying a car without a really odd scenario.

And you can’t really compare it to “this scenario” because (most?) civilized countries don’t condone the buying and selling of people.

I was referring to the “sign the title over then regret it” scenario at the top of this thread.