Not for the faint of heart, the Road to Hana is a winding, narrow road in Maui. Though it sounds intimidating, the payoff is worth it with stunning views and waterfalls. Carlos drove it during their last trip to Maui and loved it; meanwhile Joe had his first experience with motion sickness as an auto passenger and will pack the Dramamine before braving it this time!
Consider taking a hike of Haleakala Crater, one of Maui's volcanoes, to see the sunrise. Several tour groups offer the hike. You might catch Joe on this adventure while Carlos (who is not an "early bird") will probably skip this one.
If you haven't had it, Hawaiian Shave Ice is a real treat. It's not a sno-cone like in the US mainland; the ice for Hawaiian Shave Ice is really finely shaved from huge ice blocks. Then you can choose the flavor of syrup added--it's also great with condensed milk. Pure heaven!