If you know you're going to need a rental car in the near future, the smartest thing to do is to start shopping right away. Prices can change at the drop of a hat, and generally the earlier a vehicle is booked, the cheaper the price. There are other tricks and tips to help save money and hassles when dealing with dollar rent auto companies.

Paying an arm and a leg for a dollar rent auto booking isn't necessary, if you do the following things:

* Check all available dollar car rental companies in the location you will need the car. If the trip involves only local driving, even consider contacting smaller, more regional companies for pricing. Local companies sometimes offer the best prices.

* Choose a cheaper car. Large, luxury vehicles will cost you more than compact cars. This option can save dozens of dollars a day, which can really add up over the course of a two-week vacation, for example.

* Seek out discounts. Discount options for dollar rent car bookings can be found in all kinds of places. From the hotel you'll be staying in to your local auto club, they're all worth checking out to see if they have discounts available.

* Multi-bookings. Sometimes dollar rent auto bookings cost less if you rent on certain days or for a set number of days. Find out if staying an extra day would actually cost you less in the long run by asking.

* Accepting an unwanted or unpopular make car. Everyone wants the flashy rental car, but few want the boring compact. Choose a less popular car for yourself to save a few extra dollars.

* Book in advance. By doing this you can save a lot of money. Just like the airlines, car rental places will reward those who let them know weeks in advance they'd like a car.

Now that you know how to save some money with your dollar rent auto booking, it's time to consider what you'll need to close the deal. Here's what you can expect:

* To reserve a dollar rent auto booking, most companies will require a valid credit card. While you might be able to pay for the car in cash when you arrive, the credit card secures the booking. If you don't have one, see if the rental company has an alternative they'll accept.

* Valid ID/driver's license. This is a must for any reservation. Make sure you have one.

* Fairly clear driving record. While a dollar rent auto booking won't hinge on a single ticket, someone who has 20 might have a problem closing the deal.

Remember once you make your dollar rent auto booking, it's a good idea to check back a few days before you need the car to ensure it's in place. There's nothing worse than arriving at a destination to find your rental car booking isn't valid because it wasn't confirmed!