Why would you expect flames for that?
You should expect advice, though. And that is to use a site like better bidding dot com, so that you have a really solid chance of either knowing what hotel you're going to get, or what group. Like when I used them for a one night stay, I KNEW that its as either going to be the Hilton near the convention center, or some Hyatt. So I could look at their specific websites, see the charges I was likely to incur by staying there. In my specific case, both of those hotels had a hefty parking fee, and I was able to make an *informed* choice to give up my same-base-rate room at Motel6, and go with the Hilton or Hyatt and pay a bit more for parking.
It's really important to use a site like that, IMO.
If you're stuck with this hotel...why not evaluate if you REALLY need the rental car? If you're going to DLR all 3 days, are you going to be using it? We got a car once for one day; rented it from John Wayne Airport, then turned it in the next morning at the Alamo/National place on Katella. We went to Trader Joes, got DH and DS haircuts, went to Panera, did all sorts of errands in that day, and didn't need the car after that.