Search all the rental car websites and watch their pricing. They go up and down just like airfare. Sign up for their rewards programs...such as National's Emerald Isle. We used National for our last trip and was very pleased. I also tried Mousesavers.com however I was unsuccessful using their coupon codes. I've also used Costco once. One more thing....you can always reserve a minivan when you see a price you like, just don't pick the option of pay up front because then you can't cancel if you find a better price down the road. Read the fine print. Look everyday, the closer it gets to the trip, the cheaper it usually gets...sometimes.
