I used a broker and it was easy
When I bought my RS five years ago, I used a company called Auto Shipment International, based in Miami to handle the shipping transaction. They arranged the pickup in Vienna and trucking to Bremerhaven, loaded into a container, got it out of customs in Miami and I had my trucker pick it up. Another company to consider is Cosdel International, 415-543-5112 http://www.cosdel.com. I've never used them but I've heard good testimonials about them.
Things to consider when bring in from overseas:
Import duty is 2.5%....I also had to pay my state's sales tax as well. But since you already own the car, I'm not sure how that is determined.
My broker charged me $400 to get the car through customs.
Insurance is not included, so if the boat sinks you're out of luck, but you can pay the shipper to insure your car for the voyage at a rate of about 1% of the value of the car. You should check if your auto policy will cover the voyage.
On a driver quality car, consider RO RO, which is Ride on, Ride off. Much cheaper than getting a container. People will tell you that you may get dings and scratches, but its pretty unlikely (new cars are all shipped RO RO). The shipping cost of the container cost me 2.5 times the cost of the RO RO quote.
Be sure to have your tool kits, manuals, jack sent separately. The port guys often take the tools (don't ask me how I know)
Make sure you have all the original, not copies of the customs paperwork....I had to take a few trips to the license office to get my car registered. Otherwise, the whole process was easy since cars over 25 years old are DOT exempt, and depending on your state, 25 year old cars are also exempt from emissions.