In one of the other forums I'm in there is a topic about a place you put in a request and various truckers will check their schedules and if they have a spot they bid on hauling for you. May not be applicable for a finished car or maybe there are car haulers I don't know. I do know for hauling engines and misc parts these guys have had some good luck and low prices at times.
If anyone is interested in this PM me and I'll find out what it is.