I'm kind of wondering why you didn't think this out before you made your bid?
I don't think shipping companies get involved with the money but you can always ask.
Have you checked out the sellers feedback? If the seller has a lot of transaction under his belt and the feedback is good, you shouldn't have anything to worry about.
How much money are we talking about? If it's 10 hours by car, why not just fly there and conduct the transaction in person? If the car isn't drivable you can still have it shipped and just fly home.