Greg,
I've got to think that buying a new utility trailer of some sort and modifying it with cross struts and mast bracket from the old hobie trailer would be easier than all the modifications to the car. When you get to NH you could pobally sell the utility trailer without taking too much of a hit in cost, and not have to worry about the old trailer making it. I know here in Mass, I have seen new utility trailers with 4'x8' beds for about 300 bucks with the lighting equipment. Put the 16 on backwards, attach the mast strut to the front of the trailer, and you are good to go on a very long drive!
Best of luck, and you need a stop in MA or CT just let me know.
Chris Titcomb
www.acceleratedchaos.com