When you ship a car from the Mainland to Hawaii, your auto transport service starts when it arrives at port. Before leaving for driving back home with all of those precious possessions, there are some things that need attention. like The confirmation number of your auto transport service. A government-issued photo ID. The keys for the vehicle and the keys or remote for the alarm system. Registration documents for your car. A letter of authorization or power of attorney if the car is financed or leased. And The car’s title, if you’re the owner.