N.J. Stat. § 39:10-6
Every person shall have for each motor vehicle in his possession in this State:
If a motor vehicle is registered in or bears the registration plates of another state or country and is being used or operated in this State, the person in possession of it or using or operating it in this State must be entitled to ownership or possession in accordance with the laws of the state or country where it is registered or the registration plates of which it bears, and shall produce to the chief administrator documents showing title to, or right of possession in, the motor vehicle in that person or in the person who has authorized him to use and operate it, or registration certificate or other evidence of registration, besides plates, issued by the state or country or department thereof to that person, or to the person who has authorized him to use and operate the motor vehicle, evidencing the registration of the motor vehicle in that state or country.
When a motor vehicle is in the possession of a garage keeper, motor vehicle dealer, both new and used, or motor vehicle service station in this State, the production of a writing signed by the person delivering possession of the motor vehicle to the garage keeper, dealer or service station, stating that the person is the owner or entitled to the possession of the motor vehicle and has title papers or the registration certificate therefor, shall be deemed a compliance with this section insofar as the garage keeper, dealer and service station are concerned. In the case of a licensed motor vehicle dealer, the production of a writing signed by the person or persons delivering possession of the motor vehicle to the dealer, assigning to that dealer the right to title or possession or both of and to the vehicle, or in the case of a new vehicle, a copy of the manufacturer's certificate of origin, shall constitute compliance with this section.
N.J.S. § 39:10-6