US Car from Neighboring Countries

Hello together do you happen to know how this works if I want to buy an Ami in Holland or the other neighboring countries? On the net and in the forum I find only that I have to make a 21er registration but no more. I am interested if I can go to Germany with it and can register with the yellow plates to the road traffic office and then can register accordingly or must be registered in Holland before I import it? And is there anything else to b I have such a car that interests me….but I would also be grateful for internet addresses from the neighboring countries where I can find Americans.. ? Thank you very much…