Hawaii is made for road trips, and one of the best is the Road to Hana, a relatively short drive that should take all day (if you're doing it right).
Technically called the Hana Highway, the Road to Hana is 52 miles of winding two-lane road connecting Kahului with the tiny town of Hana. You could certainly make the trip in a few hours (it's slow going with all the twists and turns, and most of the little bridges narrow to a single lane), but why would you? The scenery along the way is some of Maui's most beautiful, with waterfalls to see, beaches to visit, and short hikes to do en route.
Some of the sights you can visit along the way include the Twin Falls waterfalls, the Ho'okipa Lookout, Honomanu Bay, the two arboretums, the Hana Lava Tube, and Wai'anapanapa State Park. The town of Hana itself is tiny, but lovely and has many nice beaches.
The road to Hana winds for 68 miles (109 kilometers) from Kahului to Hana on the eastern side of Maui. Another scenic stretch, Highway 31, continues to Kipahulu. Allow at least 3 hours to drive the scenic but narrow winding route. Many people take a self-driving tour of the Road to Hana, stopping frequently and spending the night in Hana before heading back to the west side of the island, but you can also book a spot on a van tour or even bike the route. Tours have less flexibility but many drivers are willing to stop where you'd like and you can also spend the entire time staring out the window at the gorgeous view. If you're interested in cycling, you can either rent a bike and go on your own, or book a cycling tour.