Friends who study law help! ! !

first of all, Mr. Wang has no obligation to pay the car wash fee, because he was not informed when parking, and the car will be washed at the same time, so the two sides did not sign a car wash contract. Therefore, there is no need to pay the car wash fee.

second, it's not unjust enrichment, because Mr. Wang didn't get any benefits in this case.

thirdly, it does not constitute negotiorum gestio, because negotiorum gestio refers to the legal fact that, without legal or agreed obligations, it actively manages other people's affairs or provides services for others in order to avoid losses (that is, losses include itself and others, or only others). The premise is that in order to avoid losses, even if the car is not washed here, Mr. Wang will not generate losses, so it does not meet the premise of negotiorum gestio.

Mr. Wang does not need to pay the consideration.