What you should do before renting your next car

If you expect renting a car to be as simple as checking a book out from the library, you're going to be in for a surprise when you show up at the rental location. While the process is (theoretically) as simple as showing your license and handing over your credit card, there are a lot of ins and outs — some of which could cost you a lot of cash.

So if you're planning on picking up a rental car on your next trip, here's what you need to know to keep your costs down.

What to Know Before You Rent

Like anything else, you should shop around when you're looking for cheap car rentals. Check prices for reputable car rental companies online as well as travel aggregator sites such as Orbitz, Hotwire, and Travelocity. When you find a deal you like, call to confirm the final price with taxes and any other fees — which can add up to quite a lot — so you know what you can expect your final price tag to be.

If you're looking for the most value, here's what you should consider while planning your trip and shopping around.

• What size car do you need? A smaller car will usually cost less, though different rental agencies will have different definitions of what qualifies as "compact," "mid-size," and "luxury," all of which will have their own price tiers. In general, the fancier the car, the higher the price tag, so look at the smallest car that will work for you.
• Do you require insurance? Though your rental agency will try to sell you insurance — sometimes at a huge cost — you may not need it. You'll want to check with your own car insurance company to see what it'll cover (full coverage policies often cover rentals you drive) as well as with your credit card company, since many — especially those with travel rewards cards — offer rental insurance as a bonus if you pay with your card. Also ask specifically about "loss of use" coverage. This is a fee rental agencies often tack on when a vehicle is damaged to cover the fact that it can't be rented while it's repaired, and it can be pricey (as much as $100 a day).
• Who's going to drive? Drivers under the age of 25 will have higher rental rates, so if possible, pick an older driver. Having multiple drivers will also cost you more — but you'll want to confirm that the rental agency knows if more than one person will be driving, because otherwise you can get stuck with liability for accidents if the wrong person was behind the wheel. Driving history can affect rates, too — or whether the company will rent to you at all. Ask your rental agency if it checks driving history, and make sure your driver has a good record if it's an issue.
• Ask specifically about "loss of use" coverage. This is a fee that agencies tack on when a car is damaged and can't be used while it's repaired — and it's expensive.
• How much mileage do you need? You may have the option between unlimited mileage (where you can drive as much as you want) and daily mileage caps (where you can drive a certain amount per day and pay per mile on top of it). If you have a good idea of how much driving you'll be doing, one may be a better deal than the other, though some agencies may not offer you a choice.
• Where will you pick up and drop off the car? Your answers can affect the price. Picking up a car at an airport comes with an extra fee, as does picking a car up at one place and dropping it off at a different place. Check with the rental agency to see what kind of fees are involved with your desired pick-up and drop-off locations, and decide whether the costs are worth changing your plans.
• Where are you going? Cross-state travel can — you guessed it — come with more fees, and international travel often isn't permitted at all. Check with your agency, asking specifically about charges for out-of-state travel, to see whether this will cost more than you're willing to pay. And, of course, shop around to see if another agency will offer you a better deal.
• What do you need? Rental agencies are happy to offer extras like satellite radio, GPS systems, and car seats, all at an extra cost. Know what you need and what you can bring yourself, rather than paying to rent these bells and whistles

And no matter where you rent or what you're renting, always check for discounts. Many agencies will offer regular discounts for memberships in AAA and AARP, alongside plenty of others, so look for discounts offered before you decide on a particular rental deal.

Fees to Be Aware Of

Beyond the cost considerations to make when planning your trip and shopping around for your rental, pay attention to the number of fees that agencies may try to tack on when you pick up the car. Here's what to watch out for.

• Prepaying for gas. You're expected to return a rental with a full tank of gas, but agencies will let you sidestep that by prepaying for gasoline. While this can be convenient if you don't have the time to fill up on your way to drop off the vehicle, it means you'll be paying for a full tank of gas (no matter how much is in the tank when you turn the car in), often at an inflated price. We recommend avoiding this if possible. To help yourself out, make a mental note of gas stations near the rental agency when you leave, as these will be the most convenient places to fill up when you return. Apps like GasBuddy can also help you find the nearest stations and the lowest prices to save a little more.
• Upgrades. When you get to the counter, you can expect to be offered the opportunity to upgrade to a better car or to add extra features to your rental. Though it's tempting, be aware that there will always be an extra fee. However, if you were hoping for a better car, this can be a time to find a bargain on it. For example, if you've reserved a compact car but the agency is running low on stock, you may be able to snag a cheap upgrade to a nicer vehicle. So if you're interested, it's worth inquiring — but don't be pressured into paying for more than you need.
• Insurance. Yes, we mentioned this above, but because you may get a hard sell at the rental counter, we think it's worth mentioning again. If you've spoken to your car insurance company and/or your credit card company, you know whether you're covered or not — and, thus, whether you need insurance from the rental agency or not. Don't be scared into getting coverage you don't need.

What to Do Before Leaving With Your Rental Car

Once you've signed the paperwork and walked away with the key to your rental, there's one very important thing to do before leaving the rental agency: Check for any damage to the vehicle.

While the agency should do this, there's always the chance something could be overlooked — and if it has been, any damage to the vehicle will be on you when you return it. Damage fees can turn into major expenses, so take a good look at the vehicle, and take photos to document the condition it's in before you drive off (especially if you note any damage).

Tips for Driving Your Rental

Driving is driving, right? With a rental, not quite. Here are a few things you need to know when you're driving a rented vehicle.

• Avoid toll roads. Some toll roads are all-electronic, meaning there's nowhere to pay with cash — instead, drivers are billed by mail. In the case of rental cars, the rental agency will get the bill and it'll pass it on to you, along with extra fees for the trouble.
• Stick to paved roads. Most rental agencies prohibit the use of their cars on unpaved roads, and if you've purchased their insurance, it may be void if you take your rental off-road.
• Be aware of your agency's policy on breakdowns and accidents. Policies vary, but you'll want to read — or ask about — the details so you know what to do in case of trouble. The rental agency is likely to charge a fee for this service, but if you have your own roadside assistance coverage (such as AAA), that may cover you in a rental, too.
• Be careful. We may be a little careless with our own cars — not entirely cautious about the sorts of little scuffs and dings you can get when parking a little too close to someone, for example, especially when driving an older car. However, this will cost you if you're driving a rental, so drive with the utmost care.

Timing Is Key When Returning Your Rental

Your driving is done and you're ready to take your rental back to the agency. This should be easy, right? Well, maybe.

You'll want to be prompt: You will have agreed upon a return date and time when you picked up the car, and you'll want to stick to it to avoid additional fees. Most agencies have a grace period of 30 minutes or so, but the easiest thing to do is show up on time and not risk it, or you could get stuck with another day's rental fee. Many agencies also have a fee for returning a vehicle early. If you are running early or late, talk to your agency to find out what your options are.

Finally, check the vehicle for damage again, and document it with your camera or smartphone. Not all rental agencies will have an agent check you out — it's becoming more likely that you'll just park the car and drop off the keys — but you still want to be sure there's nothing amiss before you go. Taking photos will help you argue your case if the agency does charge you for damage you didn't do, so be thorough with your before-and-after shots.