This is a good discussion. I am Pres Circle with Hertz and I just get a mile a dollar. Corp rate is by far the cheapest for one ways. ALso Corp rate does not permit points but for some reason does permit miles. I get AA miles on Hertz and pay Hz a few cents whereas the other airlines charge a lot more and it is not worth paying this and only getting a few miles. Also I have to take Hertz for one ways which I use a lot as no other company does the pick up and drop off points I need. So I am pretty locked down but I need to look up some of these other ideas. Often I rent for a single day when I do return to same place so National offers (for example) don't give me anything. Can you get a WN number without ever flying them - I guess you can but at one point I thought you had to fly them.