The kids have grown up and gone. They've gone and moved halfway across the country. If you want to see them—or your grandchildren—you're going to have to travel. And when you get there, you'll need a car. Then there's that great Caribbean cruise you just booked. Wouldn't it be fun to tack a few days on and drive around Florida a bit, maybe pop down to the Keys for some fishing? So of course, you'll need a car.

And so the universe created rental cars! Wheels when you need them, where you need them. The convenience is amazing. There they are right at the airport, just ready and waiting for you. Rates are pretty reasonable. You'll get a clean and shiny, low-mileage car. Usually, it will even smell new!
But before you sign on the bottom line, grab the keys, throw the suitcases in the trunk and head out, it will pay you to know what rental car insurance coverage you need —and what you don't. Don't pay for car rental insurance you don't need, but don't skimp on what you do.

Rental car companies make high profit margins on car insurance. Agents are trained to sell as much as they can. At the counter, you'll be offered several different types of auto insurance, and you might be tempted to take them all. You want to be protected in case something happens, right? Well, you may already be covered. There's a good chance your regular auto insurance policy covers you in a rental car.

Rental Car Insurance: Know Before You Go

The secret to saving money on rental car insurance is to be prepared in advance. You don't want to show up at the counter and suddenly realize you have no idea if you're covered or not. At that point, the only prudent thing to do is to pay the company's going rate for insurance—and get a nasty bottom line.

So arm yourself with knowledge. There are three calls you should make before you leave home. They'll give you the information you need to save money on car rental insurance.

1. Your Insurance Company

Ask your insurance agent exactly what your current auto insurance policy covers when you rent a car. Usually, whatever insurance you have on your own car will apply to a rental car. The same liability limits and deductibles will apply. Remember that if you no longer have comprehensive and collision damage coverage on your own car, you also won't have it on the rental. That could create a serious gap, leaving you open to pay for any losses if the rental car is damaged or stolen. In that case, you should always get the rental company's collision damage coverage.

If you discover a gap in your coverage, consider whether it might be cheaper to add it to your regular car insurance than to pay the rental company for it. Then, you'll be covered at home, and the next time you want to head out to see the grand kids, or discover an unknown corner of the country, you'll still be covered.

Be sure to ask your agent about "loss of use" coverage. While your insurance company may cover the cost of repairs if the rental car is damaged, they may not cover "loss of use." This is the amount the rental car company loses by not having the car available for rental while it's being repaired. And they will pass that charge on to you by charging you the daily rental rate for the entire time the car is in the shop and not on their lot or being paid for by another customer. There's a good chance your insurance company will not cover this. Most rental companies charge $9-19 dollars a day for this coverage, and it's often a good idea to go ahead and pay for it to cover your back.

2. Your Credit Card Company

It's almost certain you'll be using a credit card to rent the car. And there's a chance that the card includes some kind of auto insurance for rental cars. But you need to know exactly what's covered and what's not. Don't assume. As a cost-saving measure, many credit card companies have reduced what they'll cover for rental car insurance. And the coverage is often different for varying levels of the same card. A "platinum" card member may get coverage not available to a mere "gold" member. Call the toll-free number on the back of your card and ask. Then ask them to send you a copy of their policy in writing and have it with you at the rental car counter. Also, ask if the type of car you plan to rent is covered. Some cards will only cover standard cars. If you're planning to spring for a snazzy sports car or a luxury SUV, you may not be automatically covered.

If you've got more than one credit card, call them all. Coverage may vary from one card to other—sometimes by a lot. Use the card that gives you the best coverage. More bang for your buck is never a bad thing.

3. Your Roadside Assistance Plan

If you have towing and roadside assistance coverage through your insurance company or through an organization such as AAA or AARP, check to see if it applies to rental cars as well as to your own vehicle. Towing charges can be sky high. And it's good to know you won't be stuck on the highway—changing a tire, hoping for a kind soul to stop and give you a jump start, or trying to hitch a ride to the nearest gas station—if you have a breakdown. Know in advance that help will be on the way when you need it.

Armed with all this information in advance, you'll arrive at the rental car counter knowing exactly what insurance you need and when you can safely Just Say No. You'll be covered, but you'll avoid paying for duplicate coverage on rental car insurance.

Note: If you're traveling to a foreign country, whether you're planning to drive your own car or rent one when you get there, your personal insurance coverage probably won't cover you. You'll need to pay for additional rental car insurance. At the least, you should probably buy the rental agency's Collision Damage Waiver.