According to 'The Travel Detective' Peter Greenberg, calling a location directly and checking your insurance policy can help you save big when renting a car.

By going directly to your pick-up location, you have the ability to get a better deal because the company representatives are able to work out a deal with you based on what they have available.

"To understand car rentals is to understand sort of a flock of migrating birds, it's seasonal, it varies from location to location, but the one thing you have to understand is if you want to get a great deal you don't want to call the 800 number because that's just a clearing house that's going to quote you a published price and these people have no ability to negotiate."

Greenberg also thinks there is a way to get a much better deal on sometimes expensive one-way rentals, depending on the time of year and where you need to go.

"It's called a drive away deal, and these are not advertised and it's seasonal." Depending on where car rental companies have a lot of cars, versus where they need more cars, you may be in a win-win situation.

"For example in the summer months the big rental car agencies do not need a lot of cars in Florida, they need them up north, and the winter just exactly the opposite, they need them down south. This also happens on the west coast, all the way from San Diego up to Vancouver."

Greenberg says you can get a "drive away deal" for as little as $8 per day with no drop off charges, and you can choose from at least a dozen cities where the car can be dropped off at no additional charge.

Besides the rental cost itself, insurance can be another big expense associated with renting a car, but Greenberg says you may be paying for something you don't actually need, and helping the rental company make more money in the process.

"Chances are if you're already driving a car, your own automobile policy already covers you. You need to check the policy, check with your agent because if you're covered, bring that copy of the policy with you so you're not forced into buying coverage you don't need," he says.

But Greenberg cautions that not all insurance is created equal, especially with credit card companies that claim you'll be covered if you charge the rental cost to your card.

He says what they are offering is often only secondary coverage, which means it is only good for what is over and above what is already covered by your primary policy. And without a primary policy, you're usually not covered at all.

Greenberg offers a similar warning about personal effects insurance, which "supposedly covers you if somebody breaks into your rental car and steals your personal property."

He says you should avoid this type of insurance for several reasons:

  • There are so many exclusions it's not worth it because anything of value isn't covered.
  • You have to stay with the car and file a police report, which can take a lot of time.
  • The deductible is usually extremely high.
  • You're probably already covered by your homeowner protection.

There is also an ideal day to book your car rental. Greenberg says that on Saturday mornings, a lot of people who booked in advance for discounted weekend rentals turn out to be no shows, so you can get a good deal because there's a lot of cars left on the lot that companies are eager to rent out.

Finally, if you want an upgrade, Greenberg says "Unless you're a family of seven where you know you're going to need a bigger car to begin with...book the cheapest, smallest model you can, because at least in 50% of the cases when you get to that rental car location, that model is gone and they automatically have to upgrade you."