The United States government spends a lot of time deciding what is allowed into this country and Mike Solo's article How To Import A Foreign Car Legally gave a good impression of what it's like to deal with that bureaucracy.
So if I distill this "how to" article down to the actual instructions contained therein, it goes something like this:
1. Buy car in Europe.
2. Fill out form.
3. Select importer.
4. Pay money to importer.
5. Wait for car to arrive in United States.
Or to simplify it further:
Photo Credit: William Warby