Why dont any of them ask follow up questions?

Like, why do you want to go to the car wash?

We can’t assume it’s to wash a car.

Or maybe ask about local weather conditions and so on.

This to me is what a human adult with experience would do. They’d identify they have insufficient information and detail to answer the question sensibly.

>We can’t assume it’s to wash a car.

When the prompt says "I want to wash my car", we can assume they want to wash their car.