I did not remember where I found it. Just search the website. First, you need an official letter, stating that your car meets US safety standard. You can get such letter from Canada Headquarter of your car company. Tell them you want to import a car to US and your VIN number. Then you should go to the boarder and just tell them you want to import a car to US. The official will collect your passport and let you go to the office. Bring car title, car registration, Driver's license and the official letter from your car company with you. They also need you fill in a form, stating you Canadian/US address and phone number and stating that that car is for personal use and you will not sell the car within one year. They will give you two forms with the seal of US Costoms, with the Costoms Number. Finally you can bring the two forms to MVC to get the new title. It is free.
I am not sure if you can do this in the local customs office.
I am not sure if you can do this in the local customs office.