Recently I've been renting cars via the Southwest website. I click on Cars, then Special offers. Take a look next time you're renting. My last rental earned 600 SW points. My next rental will earn 1800 points. I did check other sites such as Kayak and Autoslash. I also cross checked with codes on Flyertalk. A few 1800 points rentals will yield a 1 way award ticket. FYI, YMMV. Some rates I've seen were and expensive.