I've taken it 5 times over 25 years. Seats are like 1st class airline seats. 3 choices of food, beef, chicken, fish, snacks for breakfast, club car, movie. BYO and buy the mix. Secure anything you don't want to loose. Most comments above are correct, but arrive earlier than suggested so you don't run into a problem. Take a good book or magazines, sit back an relax.
I just drove a new car back from NJ, 15 hours with gas stops only. Next day I felt it.
Some what tough to sleep with the train noise, etc.
Considering the government uses approx. $.55 per mile for an auto , a one way driving would be $550 - 600 for me plus room and food. Easier on the body, beats any weather problem.
By the way, just south of Lorton, VA, 18 miles, is the USMC Museum, Quantico, right off I95. Really worth the visit!!
"The Auto Train offers a 10% discount on rail fare to members of the National Association of Railroad Passengers and to members of any American Automobile Association (AAA) auto club. Be aware that Amtrak's normal senior citizen discounts do not apply to travel on the Auto Train. Other discount fares may occasionally be available, particularly when traveling against the predominant flow of east coast traffic (for instance, traveling north in January may result in a less expensive fare). Check Amtrak's website and look under the heading "Hot Deals" for Weekly Specials to see if any discounts are available for the period when you plan to travel"
http://www.amtrak.com/servlet/ContentServer?c=Page&pagename=am/Layout&cid=1241337915810