Your objective has explicit instruction that car has to be present for a wash. Quite a difference from the original phrasing where the model has to figure it out.
I did get it, and in my view my point still stands. If I need to use special prompts to ask such a simple question, then what are we doing here? The LLMs should be able to figure out a simple contradiction in the question the same way we (humans) do.
Which is exactly how you're supposed to prompt an LLM, is the fact that giving a vague prompt gives poor results really suprising?
The whole idea of this question is to show that pretty often implicit assumptions are not discovered by the LLM.