A few years back I was at the Wooden Boat School for the CLC kayak building class. One fellow, from the west coast, hadn't quite figured out how he was going to get his finished boat home. I think he contacted some shipping companies, and maybe even Old Town Canoe. In the end he found an instructor who was driving out to the west coast when the school closed for the winter. He traded him a Thule rack system for bringing the kayak out to him.

I'd think you could find a private party who was making the drive and would be willing to take along a kayak, for either dollars or a trade. You'd probably have less worries about packaging and loading the kayak if it was securely cartopped as opposed to loaded it in a trailer.