Quick tip: Next time you need a rental car for three or four days, rent from Hotwire and book it for a week. Weekly rates are much cheaper than 3 or 4 times the standard daily rates, so even though you're paying for a full week, you pay less total.
If you try booking this way direct from the rental company, they'll penalize you when you return the car and make you pay the daily rate plus an 'early return fee.' Boo. When you book from a third party site, the fee is locked and all they can do is not refund you any days you didn't use.
We used this trick on a recent trip to Virginia and saved over $70. Hotwire is my hero.