Where to find the lowest prices Requirements: Rent an intermediate or mid-size car with unlimited mileage for the lowest price while taking the least amount of shopping time.  I will avoid any company that lacks technology to expedite the rental and return process.  I want to see (on the first screen): the total price (including fees/taxes) from all suppliers, not just their preferred ones whether a larger car is available at the same or lower price where the car is located (on/near the airport or a long ride away) Methodology: Compare Expedia, Hotwire, Kayak, Orbitz and Travelocity.  Then check the web site of the rental car company with the lowest price to see if the price is even lower.  Recommendation: Use Kayak, it finds excellent prices and has fast & easy filtering of results, just un-check the car types that you do not want.  Hotwire may be worth checking for short notice rentals but once you reserve your car, it's not cancelable and you can not earn frequent rental points.  Hotwire uses Avis, Budget, Hertz and National so it's tough to go wrong with them.   I recommend joining frequent renter programs of Alamo, Budget, Dollar, Enterprise and Thrifty (the usual low cost winners) to eliminate waiting in line at the counter and the pressure to upgrade or purchase insurance, gas, etc. Check any special pricing that has been negotiated by your employer or association.  You may have discount codes that can lower the price (AAA, AARP, etc.).  Some codes are mentioned at various discussion threads at FlyerTalk and BiddingForTravel.  However, the code that produces the lowest price in Boston may produce a higher price elsewhere.  Most coupons that are included in your airline's frequent flyer mailing and credit card statements require a multi-day rental that usually includes Saturday.  From my limited testing with various coupons and promotional codes, they did not provide a value. Lower prices may be available at Priceline but you must do your homework first.  Find the lowest price as suggested above and then visit BiddingForTravel for excellent advice. A significant amount (20% to 50%) of the total cost is due to taxes and fees imposed by governments and airport authorities.  Remember: visitors can't vote!  I have been told that you can avoid these fees and significantly lower your costs if you arrange to get to the rental car lot outside the airport without using their shuttle.  This technique has greater benefit for longer rentals. When renting in Europe or the UK, check the wholesalers that are listed in my "Travel Links" web sites section. The following list notes a few limitations requiring extra steps: Expedia - you must re-sort the results into "car price view." Hotwire and Kayak - initial screen does not show the total price including taxes, just the daily cost.  With Kayak, you must hit the "details" button to view the total estimated cost. Don't pay for the upgrade: often rental car companies have more reservations for small cars than they can accommodate (they plan on some no-shows).  When you go to the counter, you are told that you can have a bigger car for only a few dollars more.  Politely decline and you may be given the upgrade anyway.  Being a member of their frequent renter program will improve your upgrade chances but also consider that bigger cars will use more gas. Check to see if the price went down: Most rental car companies allow you to cancel your reservation without penalty.  You may save if you keep checking to see whether the price has dropped.  If so, cancel and re-book your reservation. Migration of cars: Florida needs rental cars for tourists from late November through April.  The rest of the year, cars are needed in the northern states.  The major rental companies offer significant discounts if you pick-up a car in a northern state and drop it in off in Florida in the fall or pick it up in Florida and drop it in a northern state in the spring.  The discounts allow you to have a car at a very low daily rate.  The prices for moving a car are not posted until very near the time they are needed, so sign-up for the newsletters from the major rental companies such as Avis, Budget, Hertz and National.  When combined with a one-way ticket from a low-fare airline, it's a great way to save and have a car to drive during vacation. Finding low priced gas: If you are a member of Costco, use their "locations" button to view stores along your route.  Also check GasPriceWatch, the site has a "My Route" tab that is helpful. Check for damage before you leave the lot:  It's a good idea to take pictures of your car with your cell phone camera.  If there is any damage, get a different car before you drive off the lot. Check the fine print: When you compare car rental companies, be sure to find out what the penalties are for 1) giving the car back early, 2) keeping the car more days, 3) changing the drop-off city, 4) traveling to another state. Test was conducted on 4/25/08 and 4/27/08 City Car rental web site Expedia Hotwire Kayak Orbitz Travelocity Date Probability of getting the lowest price 60% 60% 20% 100% 40% 60% Phoenix, AZ 226 226 Enterprise 208 226 Enterprise 228 Dollar 226 Enterprise 7/12-7/19 Philadelphia, PA 221 221 Enterprise 195 210 Thrifty 221 Thrifty 221 Enterprise 7/14-7/17 Las Vegas, NV 115 115 Budget 115 115 Budget 115 Budget 115 Budget 7/14-7/17 Houston, TX 193 194 Enterprise 176 186 Thrifty 194 Dollar 194 Enterprise 7/14-7/17 Atlanta, GA 284 282 Alamo 185 271 Thrifty 284 Thrifty 282 Alamo 7/14-7/17 Detroit, MI 238 230 Hertz 178 227 Thrifty 230 Hertz 230 Hertz 7/14-7/17 Seattle, WA 389 380 Enterprise 342 371 Thrifty 381 Dollar 380 Enterprise 8/2-8/9 Boston, MA 280 280 Enterprise 276 280 Enterprise 364 Dollar 280 Enterprise 8/2-8/9 San Francisco, CA 360 360 Enterprise 310 360 Enterprise 414 Avis 360 Enterprise 8/2-8/9 Honolulu, HI 234 234 Budget 234 234 Budget 234 Budget 234 Budget 8/2-8/9 City Car rental web site Expedia Hotwire Kayak Orbitz Travelocity Date