Before you go to one of your local used car dealers, think about the money that you have available to spend. Know what you can afford for both a down payment and a monthly amount you feel comfortable with paying for financing. Work out any future payments that you will have to make in addition to the monthly payment for the vehicle. Once you have figured out your budget, stick to it. If you walk into the dealership with a firm number in mind, you will be better able to bargain with the sales person.