Motor vehicle theft, sometimes referred to as grand theft auto by police departments, is the criminal act of stealing or attempting to steal a motor vehicle, including an automobile, truck, bus, motorcycle, snowmobile, trailer or any other motorized vehicle. In some jurisdictions, theft of vehicles not customarily operated on public roads or highways, including aircraft, boats, motorized wheelchairs, and bulldozers, is not included in this category.

Methods

Some methods used to steal motor vehicles are as follows:

• Theft of an unattended vehicle without key(s): The removal of a parked vehicle either by breaking and entry, followed by hotwiring or other tampering methods to start the vehicle, or else towing.
• Theft with access to keys: Known in some places as "Taken Without Owner's Consent (TWOC). The unauthorized use of a vehicle in which the owner has allowed the driver to have possession of or easy access to the keys. Often, this is the adolescent or grown child or employee of the vehicle's owner, whom at other times, may be authorized to use the vehicle. May be treated differently, depending on the jurisdiction's laws, and in some cases, the owner may choose not to press charges.
• Opportunistic theft: The removal of a vehicle that the owner or operator has left unattended with the keys visibly present, sometimes idling
• Carjacking: Refers to the taking of a vehicle by force or threat of force from its owner or operator. In most places, this is the most serious form of theft, since assault also occurs. In some carjackings, the operators and passengers are forced from the vehicle while the thief drives it away him/herself, while in other incidents, the operator and/or passenger(s) are forced to remain in the vehicle as hostages. Some less common carjackings result in the operator being forced to drive the assailant in accordance with the assailant's demands (This method is most often used when the assailant does not know how to opertate the vehicle of choice (i.e. a helicopter or airliner). In the United States, carjacking is a federal offense, subject to 15 years imprisonment.
• Fraudulent theft: Illegal acquisition of a vehicle from a seller through fraudulent transfer of funds that the seller will ultimately not receive (such as by identity theft or the use of a counterfeit cashier's check). Many vehicles stolen in this manner are resold quickly thereafter.

Motivations for theft

Motor vehicles often get stolen for the following reasons:

• Transportation of self: For temporary or long-term use of transportation, in hopes that this use will not be detected by law enforcement. Most vehicles that are stolen are reported as soon as their owners discover them missing, therefore limiting the amount of time they can be driven without detection.
• Commission of a crime: When used for transportation in a crime, if the vehicle reported by witnesses does not belong to or have any ties to the perpetrator, and is abandoned thereafter, it cannot be traced to the perpetrator, without a study of forensic evidence that may not always be successful.
• Joyriding
• Chopping and selling parts: May be a single vehicle stolen for its parts, or a larger ring that engages in the mass theft of vehicles. Vehicles stolen for this purpose are less likely to be returned to their owners, since they have been dismantled, and the parts have either been sold as replacement parts or built into new vehicles. VIN etching or microdots may prevent this from occurring to a vehicle.
• Resale of vehicle: A stolen vehicle cannot easily be resold within the country from where it is stolen due to its registration to its owner. But shipping the vehicle across a border to a location where there is no reciprocity for motor vehicle registation may allow the thief to dodge this process.