In addition to snmx999's point, you're also not specifying that you want to wash your car at the car wash (as opposed to washing it in your driveway or something, in which case the car wash is superfluous information). The article's prompt failed in Sonnet 4.6, but the one below works fine. I think more humans would get it right as well.
I want to wash my car at the car wash. The car wash is 50 meters away and my car is in my driveway. Should I walk or drive?
I want to wash my car at the car wash. The car wash is 50 meters away and my car is in my driveway. Should I walk or drive?