Your credit report: You should already have a copy of your credit report in hand before looking at online auto loans. By law, you are entitled to free credit reports from each of the 3 major credit reporting agencies every year. Remember, free means free, not "free when you subscribe to our service." Although a lot of companies claim to offer free reports, annualcreditreport.com is the only site authorized by the Federal Trade Commission to offer truly free credit reports.

On the other hand, you don't get your credit score with this service, which is an important measure of your creditworthiness. It is probably worth paying to get a report that includes credit score. However, to avoid paying for monthly fees, look for a credit reporting company that charges only a one-time fee rather than one that charges for monthly credit protection service.

Loan pre-approval: Having a pre-approval puts you in a stronger bargaining position because the dealer knows you can get the financing you need. It helps you know how much you can afford to spend and allows you to see just how poor most dealer car loan quotes are when compared to the deals you can get on online auto loans.

New car pricing data: Know the price of the car you are going to buy before you walk onto the lot. There are plenty of places on the web that offer invoice prices on the car you are going to buy.

Rebates and incentives: Although the invoice price of the car is important, it's not the entire picture. Companies like Edmunds and Fighting Chance offer information on rebates and dealer incentives so that you know what the dealer actually paid, which is often far less than invoice cost.

Insurance quotes: Budgeting for a new car involves not just the payments on online auto loans. Insurance, especially on a new car, is a substantial expense that you need to consider as part of your decision.

Extended warranty quotes: Extended warranties have gotten a bad reputation due to hugely overpriced dealer warranties. Most people don't know that you can get extended warranties from third-party vendors that cost less money for more coverage than the dealers offer.

Laptop or PDA: This is an optional item because some people don't have the skill or interest in crunching the numbers themselves. However a spreadsheet already populated with auto loan equations lets you verify the payments you will actually see rather than trusting the dealer.

In order not to avoid getting ripped off, you have to take responsibility and be an educated consumer. You don't have to get caught in the half-truths or outright lies that dealers use to manipulate you. Take charge of your buying experience and get the best deal on your new car!