Avoid expensive add-ons to rental cars

Avoid expensive add-ons to rental cars »Play Video
Paying for a rental car is just the start. A child safety seat costs extra. So does satellite radio, emergency roadside assistance, even the privilege of using E-ZPass to pay tolls.

Consumer Reports ShopSmart checked the fees at the nine big rental companies, including Enterprise, Hertz, Avis and Dollar.

"Car-rental companies don't make it easy to find the charges on their websites. But they certainly do a great job of loading on the fees when you return the car," said Lisa Lee Freeman of Consumer Reports ShopSmart.

For instance, add a driver? That's another $13 to $30 a day. If the second driver is under 25, the fee can jump to more than $100 a day!

Lose the key, and that can cost you $375.

And be especially careful about picking up the car in one place and dropping it off in another.

"The lowest drop-off charge we found was $50. But believe it or not, in some cases avis charges as much as $1,000 to drop off a car in another location," Freeman said.

And at Avis, if you return a car even 30 minutes late, you'll be charged for nearly a full day.

With any car rental, be sure to fill up before you drop off to avoid paying extra-high prices for gas. Then you'll avoid another possible fee for refueling. At budget, it's $14.