1 Look for Deals Online

There are several websites dedicated to offering you coupons with steep discounts on car rentals.  Check out rentalcarmomma.com, rentalcodes.com, or rentalcarchoices.com for great promotions, free additional days and more.  Also, check directly with the website of the company you plan to hire from, their Twitter account or their Facebook page and you'll be surprised what they offer online that you won't hear about over the counter.   If you book online, remember to make sure that all taxes and fees are included.

2. Sign up for Loyalty Programs

The best way to access special deals and promotions is to join a rental company's loyalty program.  Not only will you save money, but you will save time as well.  Frequent travel partnerships are good too because you can earn points through affiliations with airlines, credit card companies, hotels, and others.

7. Book Early

You can always cancel, and you'll want to lock in the good rate.  This way, if you find a better deal closer to the date, you can snatch it and ditch the initial reservation.

5. Avoid Airport Rentals

Rentals at an airport often include an airport fee that you won't notice unless you look closely.  Sure, it's often the most convenient place to pick up your car, but if you can find your own way to your hotel (hotel shuttle or public transportation) and rent from a nearby dealer, you will save a considerable amount cash in the end.

6. Shop around for Regional Chains

Often times, the regional chains will offer steep discounts in order to compete with the national brands.  Do some research before you go, and you may find a local rental company with a great deal.  Just make sure to read up on some costumer reviews before you book with an unknown company.

6. Reserve the Smallest Car Possible

Many travelers don't like driving compacts and rental companies know this.  Consequently, there are more mid-size and full-size cars.  If your destination is a smaller facility, they may not have any compacts available when you arrive and will upgrade you free of charge to a larger vehicle.  If they don't, and you want something roomier, just upgrade it yourself upon arrival.

7. Check the Car Before you Leave

Make sure you check the car before you leave the rental lot.  You don't want any charges for damages that occurred before you received the vehicle.  It's a good idea to point out or sign off on any visible scratches, bumps, or malfunctions on the car so that you will not be held accountable.

8. Buy Your Own Gas

Gas prices have skyrocketed and companies may tempt you to consider an offer to pre-pay for a whole tank of gas. While it is convenient and the prices they offer are generally less than the price at the pumps, many drivers end up paying more because they don't use the full amount.

9. Study the Insurance and Avoid Unnecessary Add-ons

If you already have auto insurance, you probably have adequate coverage - if not through the policy, then through the credit card their charging you on.  Many companies will try to scare you into buying their plan and rental agencies rack up millions of dollars annually on insurance fees because travelers didn't check their coverage in advance.  Call your credit card company and call your auto insurer and see if you're covered for collisions and liability while driving a rental.

10. Return the Car with a Full Tank

Even if the gauge is just a little to the left, many rental companies will sock you will an overpriced fee to fill the car up with gas to full.  There have been reports of companies charging up to $9 a gallon to top off a tank when the car is returned.  Take note of gas stations near the rental company right away to be prepared when you return with the vehicle.