There is no countrywide or even statewide rule for abandoned vehicles. The statutes for obtaining ownership are usually defined by your state and/or town of residence. For a definitive answer contact your local department of motor vehicles and ask how to proceed. New Jersey, for example, offers an easy-to-follow, abandoned vehicle application packet.

Generally, you'll find, most abandoned car situations become a joint effort between the DMV and the police. (Again, keep in mind, that laws and procedures vary, especially when it comes to defining what constitutes an abandoned vehicle.)  

If an abandoned vehicle gathers dust on your property, you may want to try contacting the owner before involving local authorities. You can do this by recording the vehicle identification number (VIN). This can be found just inside the lower corner of the driver side windshield. Once you have the VIN, you’ll want to call the DMV and request a search on this number. If it tracks down an owner, you will have the right to contact this person about the possibility of taking over ownership of the vehicle.

If, however, no owner can be found, you’ll have to call the police. They’ll need to be notified so they can investigate if the vehicle was stolen or has any possible crime connections.

If it’s cleared, the police will then try to initiate contact with the last registered owner (and this is where the procedures vary by state or town). If no owner can be found, you’ll need to inform the police of your intent to gain ownership of the abandoned vehicle. There will then by a two or three month wait (this depends on local statutes) while the police publish notice of the abandoned vehicle, with the intent of giving the unknown owner one last chance to come forth and claim possession.
 
If no owner emerges, the police, under the statutes of recovered property, will then give you the necessary papers to apply for the vehicle’s title. You will need these papers for rightful ownership. Otherwise the DMV will not initiate title processing for this vehicle.