I think Hotwire somewhere says they start with the Expedia rating and then adjust based on customer feedback, so if it's with 1/2 a star of the Expedia rating, I don't think there's much you can do.
A few years ago, I argued with them over a Days Inn that they gave us as a 3 star, whereas all other sites had listed it as a two star. In the end, we got nowhere with Hotwire, stayed at the hotel and it ended up not being so bad after all.