We will be spending a short time on the BI, only 5 days and we're splitting it between the two different sides of the island. We're flying into Kona and therefore will need to pick up our rental there. However, our last two days will be at the volcano so I'd prefer to fly our of Hilo to get to Hawaii. Has anyone done this before? Are there certain car rental companies that are more open to this than others? Will I need to pay an additional fee?