I asked a girl if i could buy her a drink, she said I have a boyfriend, so I said, well i have a goldfish, she said what? I replied, oh I'm sorry I thought we were talking about shit that doesnt matter.
Legally importing a vehicle for race/show is only temporary. The car has to be bonded and is under the owners Visa (no, not the credit card). It's highly unlikely a US Citizen will be able to do it at all.
You bring a car in and it has to get through customs first. EVERYTHING on a foreign car is federally illegal: from the oil to coolant to tires to windshield. The EPA does not want foreign fluids on US Soil and everything has to be disposed of per their guidelines. That's why registered importers are required. If the vehicle, like the R32 and R34, are on the nonconforming vehicle list then it will NOT be allowed into the US under any circumstances.
Bill Gates had a Porsche 959 sit at customs for nearly a decade before him and Jerry Seinfeld fought long enough and payed enough money to make them federally legal, we're talking over a million spent. Good luck getting someone to do that for the Skylines lol!
All the information you need to know: http://www.nhtsa.dot.gov/CARS/RULES/IMPORT/