The one and only time we used them, they gave us a car on which the rear door decided to not work after we got in it. It was a Santa Fe, if I'm not mistaken. When we called them, they told us we had to bring it back to the rental site and they'd exchange it. The next day, we stayed in the park until around 4 and DH brought the car back. They then proceeded to try to charge him for the gas used. He explained that he was exchanging the vehicle because we couldn't get the stroller into the back without a working door and that we'd only gone to WDW once. All the gas that was used was used to pick up and return the car! They told him too bad, because he had to return with a full tank. He finally left, filled the tank and then returned the car.
When we returned the car, I asked for a manager and explained what had happened. I told him that we always rented from Payless in Las Vegas and never had any trouble. He did take 10% off the rental price and refund what it cost DH to fill the car upon the first return, but I'd never go through the trouble of renting from them again.