I was booking our HNL accommodation for last month through Hotwire as I was giving the mystery hotel thing a go. Comparing rates I noticed that some HNL properties had a resort fee as it would have a total AUD amount for the accommodation then directly underneath tell you eg "a resort fee of US2.00 per night applies so USD80.00 is paid to the hotel direct."
The hot rate I was looking at definitely didn't say anything about resort fees so I assumed there wasn't one or if there was that it was included in the taxes and charges which were approx AUD140.00 which was a lot more that the Hawaii state tax on nightly room rates.
I took print outs of all our accommodation bookings and brought on the trip with us. Our hot rate hotel in HNL which is a mystery hotel turned out to be the Coconut Waikiki Hotel which was revealed upon payment which is at the time of booking and non-refundable. When we checked in to the hotel they mentioned the resort fee but when I told them there was no mention of any resort fee having to be paid direct and they agreed that it must be already included in the charges and I thought that was the end of it.
When we went to checkout of the hotel 4 days later a different staff member was on reception so was insisting that we had to pay US80.00 in resort fees (4 nights @ $20.00). While SO was discussing that with reception I was calling Hotwire on Skype in the lobby and when I got on to someone in the call center they were no help and just kept repeating a scripted response of "you agreed to the terms and conditions at the time you booked." Yes I ticked the T&C's box that said there may be additional fees and charges payable direct to the hotel however it is Hotwire's duty to fully disclose what the amount is that is to be paid direct, particularly when we're talking about resort fees which are not insignificant. It's not like you can double check first direct with the property when you are booking a mystery hotel.
If Hotwire can display the resort fees for some hotels they should display it for all hotels so consumers can accurately compare rates and make an informed decision about which property to choose. I was still on the phone to them getting nowhere when SO came up and said "they've agreed not to charge us so let's go before they change their mind." We still had to drop our rental car off at Thrifty before getting the shuttle bus from the depot to the airport terminal.
I mentioned to SO in the car "wow, someone was looking after us" and it was then he mentioned that while at reception finalising the account he noticed an envelope on the front counter awaiting collection with his mother's name on it. She passed away in 2003 so I never got to meet her but I'm sure it was some kind of devine intervention.
So the long and the short of it, I would still use Hotwire again but would be extremely cautious in using them in a city like LAS or HNL where resort fees apply. If I did use them I would probably only choose an option where it specifically mentioned the actual amount of the resort fee to be paid direct and would not book one that didn't disclose this nor assume (again) that there wasn't one just because it wasn't mentioned.