First of all, this drive is officially for 4WD vehicles only. If, theoretically, one took a 2WD convertible (I'm not saying that we did, but we..uh...we know some people who did), don't go after a storm when the roads are muddy, and expect a lot of strange looks from the few trucks you'll run into.
The road starts to wind up through farms and grazing lands, dry and dusty but beautiful in their desolation. Once you make it to the forest, you'll see a pull-off and a fence by a fantastically carved wooden totem pole. This is the workshop of Robin the Woodcarver, who will show you his lovely hand-turned bowls and wooden sculptures, as well as draw you a map of the local attractions.
You should be albe to make it to the Waikolu Lookout, just beyond the Sandalwood Pit, by car, whatever the drive train.
After this point the road gets sketchy even for 4WD vehicles.
If it's clear at Waikolu, and you have time and provisions, you could take the 5+ mile path to the awesome views from the Pelekunu lookout. There's a wood plank path through the lush vegetation of the Rain Forest, so no machete is required.
For the less adventure-prone, the adventure desk at the Hotel Molokai offers guided excursions of this area for around $50/pp.