The credit union idea is a good point- I'm a member of a credit union, and my mother has excellent credit there. With her cosignature we could probably get a very low interest rate.

Personally, I'd love to wait until the end of the month, but I'm not sure our car is going to last that long- and when it goes, its trade-in value will be zero. As it is, I'm liking First Financial's car buying program.