Check out mousesavers.com for lots of codes and coupons for various rental car places. Check, check, and recheck as your trip gets closer, because many of them start dropping their base rates as the trip gets closer.
For me, for instance, with a February trip, the coupon codes I see right now are for rentals that end just before I need them. In another couple weeks, the new coupon codes will start coming out (or, rather, National will start extending the expiration dates of the same coupon codes), and I'll continue to check and recheck.
I would far rather have a car than not have a car. Although it wasn't the family's *worst* experience with the buses, leaving AKL to get to Epcot one morning was about the second worst, with multiple buses for the other three parks coming and going, with NO buses for Epcot for a long, long time. It was not much fun at all. Every time I thought "forget it, I'm getting the car" I would see another bus or two pulling in, I would stay in line, and then it wasn't for Epcot. Then I'd start the thoughts all over again.
I don't think you could pay me to take another bus from there.
And the one night we used the bus to get back to Jambo, even just from Kidani, it was miserable.
We also like going shopping for groceries and, as of our last trip, kitschy souvenirs from places like Gift World. (I got the most fun Florida magnet last time) And we enjoy eating at Sweet Tomatoes at least twice in a trip (we take long trips), which doesn't *require* a car, but since we don't want to take a bus to DTD then cross the street and walk towards the back of the parking lot, a car is *nice* for that.