http://itunes.apple.com/us/app/carfax-reports/id479267592?mt=8 - Before you buy a used car, you need to find out how companies like Carfax can help. Car fax for example helps you locate dealerships or sellers you can buy used vehicles from. Go to their website, carfax.com to do a free VIN check on the car you are interested in. Carfax helps you find the used car that will suit your needs.