You want to be flexible about your travel plans as much as possible. It could save you a lot of money. Some rental companies have weekend specials. You probably will find the best rates during the off season.

The small car is usually cheaper than the big one. So it is wise to book the smallest car that you will need. Sometime the rental company will give you the upgrade. However, you might want to check into other size class vehicles. Sometime the rental company may have extra cars in a certain class, and they may offer discounts.

If you can find coupons, you should use them. Make sure you read them carefully for exceptions. Most upgrade coupons are based on availability. If you have upgrade coupon and monetary discount, you should take both of them with you. If the rental company does not give you the upgrade, they may give you the monetary discount instead.