what's the US regulation for importing cars from other countries? is it 15 years or 20 yeasrs old?

i was just looking at a couple sites, and saw that australia and canada is 15 years.
cuz if it's 15 for us too, i'm thinking about importing a 180sx.

 

I dont think that rule applies to the US, nor do we have one based on age. I know up north they are getting R32s now due to the 15 year rule.

 

up north... as in northern cali? northern america? or canada?
i could've sworn that US had an importation regulation on the age of cars.... but hey.. i could be wrong.

where area are these r32s found in?

 

I want to say that there is. In Canada its 15 years. In the states its either 20 or 25 years. I dont think Motorex would try to legalize a 1970 ish Skyline.

 

http://www.customs.ustreas.gov/