I think there's high pressure from the National/Alamo management at DFW to produce revenue. This is evident by your experience as well as mine. I would also caution you to examine your car carefully for damage prior to checkout. The checkin staff are particularly nit picky. Coincidentally, the checkout area is in a dark, poorly lit garage while the checkin area is on the garage rooftop with plenty of sunlight to help spot the slightest imperfections.