Getting it to the US is easy. Registering it and getting it insured and everything can be a nightmare if you don't know the right people. You can spend the better part of a year asking all the people and agencies involved, be told it's fine, then bring it over and spend 6 months to only find out you're actually fucked. The good thing is that in America it usually just comes down to cost. Like buying a new carburator identical to the Japanese one but with an American market serial number on it. If you can find a business that regularly imports cars you can have them import it and just sell it to you. A business that does it several times a month will not only know what paperwork to push but the government employees in those offices will be familiar with them and everything will go smoothly. You try and do the same and suddenly every idiot along the way will nit pick wherever they can.