It is possible to research a vehicle's VIN on Carfax or through Experian's AutoCheck, in order to find information about the car's title, accident history and mileage checks. These resources charge a fee to access the information. The National Motor Vehicle Title Information System provides a vehicle's title information only.
The federal government requires certain entities to report title information about vehicles, but not all cars are in the federal database. Checks allow buyers to determine if the vehicle has been marked as salvage, which likely makes driving it illegal. When searching for a VIN, it's worth checking the VIN on the engine and the VIN on the driver's-side door or underneath the dashboard, to make sure they match. A mismatch indicates that somebody replaced the engine.