Found this on Youtube--this captures the essence of what driving this highway is like very well!
Supposedly, rental car companies state that if you drive this road, you void your contract (and any extra coverage you signed up for when you rented), and they also will not come to your rescue if you break down while on this section of the highway which links Kapalua to Wailuku.
But man, what a stretch! We rode on a bus during a hiking tour a few years ago which traveled this road, and it was a photographer's dream.