Major Booking Sites

While many of the options I will outline below have the potential to trump the big sites, the major booking sites are still a good place to start your search. When appropriate, searching on "Flight and Car" together, or better yet "Flight and Hotel and Car," will help you tap into the universe of vacation package and bundled discounts. These can be both compelling and competitively priced, especially with the added attraction of one-stop, time-efficient shopping.

Read on, however, and you'll see that the big booking sites are probably best used to get a sense of the lay of the land. In my research for this article, I would estimate that nine times out of 10 I could find a slightly better deal on a rental car elsewhere. In some cases the savings were along the lines of about five bucks a day, which is not necessarily a deal breaker for the convenience of booking a car and being done with it -- but if you're seeing very high daily rates, as I did in several searches, it's time to look elsewhere.