A used car buyer may know how to find the best models and how to reach a fair price, yet not know how to buy a car on credit. A buyer who walks into a dealership with insufficient information is likely to accept dealer financing and pay top dollar for it. Savvy buyers need to comparison shop for money just as they do for the car itself. The easiest way to get information about used car loans is to phone various sources. Provide the pertinent information: cost, description of the car, and the down payment. After you have discussed the loan length and the amount to be borrowed, find out the APR and what the monthly payment on that amount will be. Find out if there are any restrictions on the amount of money the creditor will lend for the car you are interested in. Also, ask about additional fees such as credit checks and the finance charge, which is the total cost of the loan.