There was a time all my car rental credit went to UA and AA, with a little of USAir and * Starpoints thrown in for good measure. Lately, I've been finding good car rental prices on the SWA website. In some cases, they're offering 1200 points. I have lots of AA/US/UA miles, so the extra miles don't really add up. Starpoints from Avis are always a good idea. Since I dont have many Southwest points, and since a few rentals can and does make a difference, I put the points here. If I book far enough in advance, SW has pretty low mileage redemption rates. I recently booked a 2880 point redemption on a 1 way flight SAN/LAS. Not a bad way to spend some points that came relatively cheaply. Earlier in the year, I booked, but didn't fly a 1 way LGA/MDW for ~5000 points. I like the fact that I can cancel my reservations with SW, and have the points put back into my account. It's like I'm 1k on UA. Over the years, something comes along every once in a while to open my eyes. Something that makes this long time flyer think out of the box. It's a lesson worth learning. I'm glad I'm diversified.