its standard emissions that let the faff down when it comes to being released in US, they are too high. It was the same for many japanese manufacturers, the skyline R32, 33, 34 were never allowed over there iirc for the same reason, the US has a 20year law after that amount of years has passes since the car was released you can import that model over there, so the US have 5 more years to wait before they can bring in a faff, Canada has a 15year similar law and they are just receiving their faffs as of 4months ago.