Hana drive -- Great driving route. esp if you love long drives. Lots of waterfalls in the road. Carry extra clothes, towels, sun block. Carry little food and beverages as there arnt many restuarants on the way.
Towards the end there is a small restuarant called 'Island Chef'..loooks like a tiny place but awesome food and reasonable prices ($15-$25 per dish). Definitely do the small hike to the red sea beach. You cant really spot the trail/beach easily. We got some locals to give us direction.