(MONEY Magazine) – Attention, car shoppers: Wonder what that is going through the moon roof? It's car and truck finance charges, which shot up 7.3%, to an average rate of 8.2%, in the five months that ended in late July. That's the largest five-month increase since 1989. Can you still find a good deal on an auto loan? Yes -- if you shop around. Nearly 80% of all car buyers arrange financing through the dealer, who often stacks two percentage points on top of the APR (annualized percentage rate) the bank would charge. Here are a few alternatives: -- Credit unions. Car-loan rates at the nation's 12,800 credit unions averaged 7% during the spring rate run-up, nearly a point less than the average rates at banks and S&Ls. Credit unions have become more flexible about their membership; call the Credit Union National Association (800-358-5710) to find out if there is one nearby that you can join. -- Manufacturer deals. Car companies have lately been luring customers with APRs as low as 3.9%, depending on the car model and the state where it's purchased. In July, for instance, the Chrysler Corp. was offering 3.9% financing on its 1994 LeBaron, Plymouth Voyager and Eagle Talon models. John McManus, editor of CarDeals, a consumer newsletter on car and truck incentive programs (202-783-3001), notes that a low-interest finance plan will often save you more than a cash rebate. -- Home-equity loans. In 1993, 13% of all home-equity loans were taken out to pay for a car. One reason: The interest payments are tax deductible. The average rate on a home-equity loan is now 8.6%; when you figure in the tax savings, assuming you're in the 28% tax bracket, that comes out to 6.2% -- lower than a regular car loan. But remember: If you can't make payments for any reason, you stand to lose your roof, not just your ride.