Can you explain that further? What is not legal about them? Can't you get a letter from the manufacturer stating that they meet the US emissions and crash standards?
Here's the response from the second importer to respond to me:
Right hand drive cars are not able to be imported without a letter from the manufacturer regarding fmvss 208 or crash data submitted to DOT. www.nhtsa.dot.gov/cars/rules/import
They have a hotline on this website if you have more questions.