1) You do not need to purchase the additional insurance
Most people do not realize that their own insurance will cover the cost of the damage of a rental car if you get into an accident.  The only thing you may be responsible for is the deductable, which will be the same as if you got into a crash in your own car. 
However some car rental companies charge you the rental charge per day until the car is completely fixed, which is called Loss of Use.  They do this because they cannot make money renting it out until it is repaired.  Make sure your insurance allows coverage for that.   

2) Use your American Express
American Express is essentially their own rental car insurance company, because if you get into an accident they will take care of the insurance coverage.  They are the same as the insurance policy that you purchase from a rental car company.  Visa, MC and Discover may have cards that may cover rental cars, but you should call your credit card company to make sure.  Also, make sure the AX you are using includes the car rental insurance.
 
3)  You can upgrade, you are the customer
If the car you reserved is not available, most if not all companies will give you an upgraded car at the same price as the car you reserved.  Remember you reserved it, therefore if they do not produce it they should give you the same if not better for the same price.
 
4) Understand their fuel policy
Negotiate the gas beforehand.  If you think you may bring back the car on an empty tank, let the car rental agency know ahead of time and you may be able to pay $5.00 a gallon rather than $10.00 a gallon or more.
 
5) Additional miles
Some car rental companies give you X amount of miles per day.  If you believe you are going to go over that amount, you can negotiate extra miles per day at a fee.  Just remember if you do not use them you still need to pay for them.
 
6) The more days you rent the better the price!! 
This concept is similar to hotel packages, offering price incentives for more rental days.  Remember, this is a win-win deal, you can vacation and enjoy your exotic rental car longer at a lower daily rate!  Just ask them for their discount rates for multiple days.
 
7) Call the car rental companies direct
 Try not to use a travel agent, concierge, or car rental broker.  By dealing direct with the company there is no middleman taking a cut, leaving more room for the car rental company to negotiate with you.
 
8) Book in advance
If you choose to book your luxury car rental ahead of time, most rental companies will give you a better deal.
 
9) Ask for specials
All car rental companies have some sort of specials going on.  Just need to ask.
 
10) Hooking you up with your rental
Some car rental companies will provide a drop off or pick up of your car.  Ask ahead of time as you may be able to get the rental car delivered right to your door.
 

Post by Imagine Lifestyles Luxury Rentals