By Elizabeth Millard

When zipping from airport to business meeting to hotel, the best form of transportation is often your own set of wheels—well, borrowed wheels, at least. Rental cars can be very handy for exploring an unfamiliar city and for arriving on time to client lunches, but they can also be costly for the frequent traveler. Here are some tips on making sure you get the most value from your temporary ride:

Don't let anyone else drive
If you're truly in the mood to stay budget conscious, but you're traveling with other people, assign one person as the driver. Putting additional drivers in the contract adds up, and if there's a problem when a non-registered driver has taken the wheel, then not only can the car rental agency make a claim against you, but so can your personal car insurance.

Give the car a look before leaving the lot
Most rental agencies do a quick visual inspection of the car to note any scratches or dents, but agents can sometimes miss notable damage. Before you set off for that meeting, take a few minutes to walk around the car yourself and make sure that if anything looks bruised or battered, it's noted on the contract.

Know the terms of the contract
Sure, it's a long document with teeny writing, and it would be easier to just stuff it in the little paper folder and forget about it. But to squeeze value from the rental car and to protect yourself, take a few moments to read over what you're signing. Often there are mileage restrictions, statements about prepaid gas charges and even restricted activities, like towing a trailer.

Schedule properly, and return it on time
Rental agencies lend out cars based on a 24-hour clock, so understanding the rental time length is important. Returning the vehicle just an hour past deadline often results in an entire day's charges added to the fee. Ask the agent when it's supposed to be returned and what the policies are for notifying the company if you'll be late. Some agencies will waive extra day fees if they're informed in advance about a time change.

Reserve in advance
Many times, travelers think of the rental car as the last detail in an travel arrangements’ list that includes airline tickets and hotel reservations. But booking the car as far in advance as the flight has its benefits, including taking advantage of special discounts and being able to secure the type of car you want. Reservations made late could mean limited car availability, which usually translates into getting a more expensive car than anticipated. So, if you're yearning for an affordable, mid-size vehicle and don't want the keys to an SUV, book early.

Love the Web
Booking sites like Travelocity gives travelers a good idea of general rates. But if you have the time and the inclination to save some money, visit the sites of each car rental company. Most encourage online booking and offer discounts—sometimes up to 10 percent—for going through their site. Also, as peak rental times change, many create short-term deals that you can nab as a reward for your surfing diligence. Be sure to check the details before booking, though; some "deals" have restrictions based on rental location or car size.

Befriend the agent
At many companies, agents get a commission based on what type of upgrades or insurance they can sell. This gives them wide latitude for tweaking rental rates, giving free upgrades in car category or changing some contract terms. Although this should also put the traveler on alert for the art of suggestive selling, it also means that your new friend, the rental agent, can help to negotiate a better deal.