The island is very driveable. Tops on the list...the Grand Canyon and the northern Napili coast region. Easy hiking trails to fantastic overviews on the canyon park. Just like in the US, the canyon colors change with the sunlight. On the northern Napili coast you'll find easy access to world renowned beaches but especially unsafe for swimming in the winter with strong currents. The southern Poipu area is more luxury hotels with calm beaches and expensive B&Bs. They've added restrictions to make the heli rides much safer than in the 90s when you'd get right next to the canyon walls. I went then not knowing the dangers. Killed lots of tourists and Viet vet pilots.
My favorite Hawaiian island.