It might come in handy to ask about cars from other areas if you find yourself having to do a one-way rental. I had to do a one-way rental from BWI to CVG due to a flight cancellation. I asked the agent if they had any cars that needed to go back to CVG and I was offered a full size at the compact rate with no drop-off charge. Probably saved me a couple hundred dollars.
At LAS recently I noticed quite a few out-of-state plates on cars in the rental lot.