To find a Mustang's vehicle identification number, look inside the engine compartment under the fender on the driver's side of the vehicle or inside the car just above the dashboard. Additionally, check the data plate on driver's side door, or find the partial VIN on the back of original engine.
A pre 1968 Mustang may not have the VIN on the dashboard or on the engine. A 1968 Mustang has the VIN on the dashboard on the passenger side of the vehicle, whereas the 1978 and later models has the VIN on the driver's side. The most valuable place to search is the door jam where the data plate is stored. The data plate along with the VIN provides other essential information about the Mustang.