I'm not sure why you were downvoted either but I suspect it was for the same reason I was for asking similar questions.
As you point out from the faq, the onus seems to be on the owner and the only consequence for the dirtiness is the ability to rate the user. I think a more serious question relates to the adjudication process in the case of more serious violations such as scratches, damage or theft of items from the car. Do they automatically take the word of the owner - and what happens in the case of false claims against a renter by an owner - what appeal process does the renter have in that case?
As you point out from the faq, the onus seems to be on the owner and the only consequence for the dirtiness is the ability to rate the user. I think a more serious question relates to the adjudication process in the case of more serious violations such as scratches, damage or theft of items from the car. Do they automatically take the word of the owner - and what happens in the case of false claims against a renter by an owner - what appeal process does the renter have in that case?