its 1 year....
the cars you see is probably people that brought them over from their country of origin over here.
You can have a car here on foreign plates for a period of 12 months.. then you have to register here or take it back and then return here again..
as long as the car in question pays road tax and insurance in the country of origin, and the insurance covers to drive over here, then all is legal.
I had my portuguese car over here for 3 years, never had any problem. was stopped a few times, showed the papers, proof of insurance and road tax paid and was let go on my way..
