I am pretty sure the way it works is if the winner actually wants the Lambo it will be bought in the country of residence. There is no point in buying a lambo in Europe and having to pay shipping and customs to send it to USA and then later on before it can even get registered it needs to get modified to pass emissions.

Most likely unless the winner is some whale, then the winner will most likely just go the cash route. This is how most car contests are held. Most of the time the winners can't afford the insurance, maintainance, gas on an exotic and they would sell it anyways. Lambos are different from other cars. You can't just buy it and do no maintaince or do the maintainance yourself. Because it will lose value because every buyer checks the receipts before they make a purchase. Unless its done at a Lambo leader, the price will tank of the cars value.