The concept of loading an automobile into a container and then putting that container on a ship to go across the ocean is somewhat bizarre to me. But, I guess it happens regularly.
I used to help a friend maintain her 1929 Ford Model A roadster. She decided to sell it and the best offer she got was from someone in The Netherlands. The buyer sent a trailer to pick up the Model A. The car was delivered to a shipper in New Jersey who put the car in a container for overseas shipping. The car arrived OK and the buyer is happy with his purchase.
What issues will you run into when your Expedition reaches a dock in Europe? How difficult will be to get the vehicle through your customs agency? Will the vehicle have to be modified to suit Polish automobile rules?