A few simple strategies will prevent you from being fleeced in the dealer's finance office. By Mark Solheim, Senior Editor January 31, 2007 In the Internet age, finding new-car data to use as haggling ammo is easy. But many buyers who spend days whittling the sticker price let down their guard and hand the savings back when they accept a dealer's car-loan rate. It's easy to see why. The rate you get depends on information that's not always easy to come by. Plus, dealers put their most talented closers in the financing-and-insurance office, where you are subjected to a rash of offers for extended warranties and other add-ons as well as a blizzard of paperwork that can exhaust you into submission. SPECIAL: 2009 CARS The 2009 Cars: Deals Are Insane SLIDE SHOWS: Best Cars for 2009 EXTRA: Green Machines 2009 MORE: Kiplinger's Car Buying Guide Dealers have also been known to bump the rate above what you should pay based on your credit history. If you qualify for a 6.5% rate but the dealer charges 8% on a 60-month, $20,000 car loan, you pay $900 more in interest. That's extra profit for the dealer. Where do you stand? The interest rate you pay depends on the credit "tier" you fall into. Tier A and sometimes tier B borrowers get the best rates; E borrowers pay up to 30% interest. On five-year loans, A-credit customers shopping for a new vehicle could recently command rates of 6% to 7%, or as low as 0% on vehicles sporting low-rate incentives. The tier you fall into depends mostly on your credit score, so the first thing you should do is research that number. You can get a free credit report once a year from each of the big-three credit bureaus at www.annualcreditreport.com, but you usually have to pay $6 or so to get your credit score. FICO scores, the most popular flavor, range from 300 to 850. About half of all car buyers who finance a vehicle have a score above 720 (tier A), according to a study by the Consumer Banker's Association. Another 25% beat 680 (tier B). If you have a borderline score, you could be boosted into a higher tier if you make a sizable down payment or shorten the loan term. In the U.S., the average down payment for a car is $2,400, the average amount financed is $24,864, and the average monthly payment is $479, according to Edmunds.com. The most popular loan term is now a payment-stretching six years. If you're "upside down" on your old car loan (you still owe money on it after the trade-in), it's no longer a deal breaker. In these days of easy credit, lenders will roll the old balance into the new. Nor are down payments de rigueur; you can finance up to 100% of the manufacturer's suggested retail price plus taxes, tags and fees. Avoid the traps A few simple strategies will prevent you from being fleeced in the dealer's finance office. Your best bet is to have a good loan rate in the bag before you even set foot on the car lot. First, find out the annual percentage rate you qualify for, and then get pre-qualified for a loan from your bank, your credit union or an online lender, such as E-Loan or Capital One Auto Finance. If the dealership can't beat the rate, politely decline its loan. A corollary is to keep all transactions -- price of the car, value of the trade-in and financing -- separate. If you let the dealer merge them, it's tough to know if you're getting the best deal on each one. And a dealer who knows how much you'd like your monthly payment to be can play with the price, options, trade-in value and interest rate to come up with what you budgeted -- often by extending the loan term. See Wheeling and Dealing to learn more about how to negotiate your deal. Should you take a low-rate-financing incentive instead of a cash rebate? Zero percent is hard to beat, but if your loan rate is low, say 4.9%, the decision is tougher. One rule of thumb is to take the cash if you plan to keep the vehicle less than three years. But run the numbers on an Internet calculator such as the one at kiplinger.com/links/carincentive. Writing a check from your deductible home-equity line of credit isn't always a good strategy now that average interest rates are about 8.8%. It's probably better to keep the home-equity funds intact for a home-remodeling project or financial emergency.