We used Dollar at the end of January and they are in the garage across from the terminal (this is considered On-Site). If you sign up for Dollar Express you head straight to the garage and you can be on your way in under 10 minutes with no up-sell.
We got a Chrysler Town and Country, it was clean, drove well and only had about 5K miles on it. We rented for 11 days and only paid $208 plus I got $8 dollars back through ebates-cash back.