With airfares and hotel rates rising last year, it's some consolation that prices for rental cars actually decreased on average and are expected to remain about the same in 2013.
The average price of a car booked on Hotwire late last year was about $27 per day, down 3 percent compared with 2011. And while prices for rentals during the recent holiday season were higher -- roughly $40 a day -- that's still 6 percent lower than a year earlier.
Despite more consolidation in the car rental industry -- Hertz purchased Dollar and Thrifty last fall, and the Avis Budget Group is buying Zipcar -- consumers may not get hit with the higher prices that often accompany these deals.
The trade publication Auto Rental News recently predicted "a ground war on rates" in 2013 as the major car rental companies compete with independent brands like Sixt and Advantage, especially for airport rentals.
One factor that benefits travelers in this equation: the industry's lack of change fees or cancellation penalties, which means customers are free to look for a better deal right up until they get behind the wheel.
Some airports have made it even easier to be fickle, by locating all their car rental companies at one facility that's linked to the airport by the same shuttle bus or train, a growing trend that Miami and Seattle have recently embraced.
But it still takes some effort to find the best price, partly because Web tools to compare car rental rates aren't nearly as sophisticated as their counterparts for flights and hotels.
Here's some advice on tracking down a good deal.
Recheck your rate
"Book early -- and often" is a good mantra to follow, particularly if you need a car during a peak travel time.
I booked a car on Nov. 9 for an eight-day rental in Detroit around Christmas, and even after repeating my search and trying every coupon that landed in my inbox in the ensuing weeks, I couldn't beat the original price, $218.
Jonathan Weinberg, co-founder and CEO of the car rental site AutoSlash.com, said holidays can be an exception to the usual pattern of price volatility, which often includes a decline.
"Rental car companies will typically set the price high and those prices will almost always drop," he said. "The best way to game the system is to book as early as possible and recheck the rate."
AutoSlash set out to automate that process for consumers, even going so far as to automatically rebook a reservation after finding a lower rate.
But after car rental companies protested, Mr. Weinberg had to revise his business model; he promises a new version of the service this year.
Until then, AutoSlash can still track a reservation you booked elsewhere and will let you know if it finds a better rate; you just have to do the rebooking yourself.
As I was planning my December trip, I was surprised at how little most travel sites are investing in their car rental comparison tools. Mr. Weinberg said that's because the commissions agencies get for car rental bookings are so low: about 2.5 to 5 percent of the rate you book, versus 10 to 40 percent for a hotel.
Still, there are a few innovations worth checking out, especially if you're looking for an off-airport rental.
Kayak recently added a "map view" option to its car rental results, which makes it easy to see the location of various neighborhood dealers and to decide whether it's worth traveling farther from your home or hotel to pick up a cheaper car.
"Using the map view, you can zoom in and look for certain neighborhoods," said Jessica Casano-Antonellis, a Kayak spokeswoman, adding that you can also limit your results to points of interest, for instance, car rental locations within a half-mile of Faneuil Hall in Boston.
For visitors to New York -- or for New Yorkers looking for a local rental -- that's a helpful tool, since searching for a ZIP code or address in Manhattan can turn up locations in New Jersey and Staten Island as well.
But if you're willing to travel across the river, Jersey City can be a bargain: I found a three-day weekend rental at a Budget location in Jersey City for $111, compared with $471 at the Avis location closest to me in Brooklyn, or $252 at an Enterprise, also nearby.
Hotwire tended to have the best deals in the searches I tried, while CarRentals.com displays more of the independent companies others don't always include in their results, like Ace, Advantage, Fox, Payless and Sixt.
Most travel sites don't work with all of these companies, and some don't even include all the major brands.
For instance, Orbitz doesn't show results for Enterprise, National or Alamo, while Expedia doesn't include Avis or Budget, so don't assume you're seeing all of your options if you search only one site.
A new site, Zalyn.com, promises to show you coupons that apply to your rental dates but asks you to first enter the lowest rate you can find from 10 different car rental companies. You can skip that step (for less thorough results) or check the coupon section at AutoSlash, which lists dozens of car rental deals, like weekend rates from Enterprise starting at $9.99 a day.
Look beyond price
According to the 2012 J.D. Power and Associates rental car satisfaction study, about 4 in 10 leisure travelers choose a rental car company based on price, but there are other factors like customer service and fees that are worth considering.
The study ranked Enterprise highest in terms of overall customer satisfaction with processes like reservation, pickup and return, as well as price, followed by National and Alamo (both brands are owned by Enterprise), then Hertz, Avis and Budget.
"Enterprise has been the top rated for the past few years, with the exception of last year," said Ramez Faza, senior account manager for global travel at J.D. Power and Associates. In 2011, Ace Rent-A-Car, an independent company, had the highest ranking but fell to eighth place on the list last year.
Mr. Faza noted that independent brands like Ace have fewer locations than their better-known competitors, so one or two bad operators can more easily drag down the reputation of the entire brand.
Still, the lower rates independent companies typically offer can mean shortcuts in customer service; review sites like Yelp can help you figure out if an unfamiliar brand gets low marks.
Other factors to consider are whether your rental includes unlimited miles, if there are any restrictions on where you can take the car (some Enterprise locations limit drivers to nearby states) and operating hours.
Off-airport locations sometimes close early on weekends, so you may have to pay for an extra day if you're running late.
If you expect to share the driving on your trip, Mr. Weinberg suggested investigating any additional driver fees, which some companies like Avis, Budget and Enterprise waive for a spouse or domestic partner.
"With Dollar and Thrifty, there is really no good way to avoid the additional driver fee," he said. "With many of the other companies, it's often included for free."travel