in maui, go for scuba diving at molomini,you'll see many kinds of fish, hills under sea, and whales jumping on the way there;
then drive up haleakala(?), which is more than 3000 meters above sea. you'll see clouds and vocanoes below you. you can even ride a bike down;
drive up northwest to kahana, see some rain forest land scapes;
if you still have energy, drive down hana, in the evening. hahahaha...
generally food is expensive but bad...
hope these are helpful.