Being a fan of a car make that isn't currently imported into the US, I'm always interested in tales of "bringing them over anyway." However, I've read enough of them to know that, as they say, "it ain't easy." Those of you with equal interest in importation but less familiarity with the lovely federal beuracratic process should find part 1 and part 2 of one man's attempt to import a Ferrari F-50 race car illuminating.
The delay and enormous expense the EPA and DOT put this guy through over a car that was never meant to be driven on the street is amazing. All the hundreds of pages of regulation in both agencies regarding this end with, in essence "unless it's a race car, in which case you can just ignore all of the above." However, as this tale relates in at times eye-crossing detail, you're not the one who gets to determine what is and is not a race car.
The articles are three years old now. I can't find any later comment on whether or not the thing was finally allowed in, but I'll let you know if I do.