You must go to the old lahaina luau.It is the best. Probably you should book from home. Pass on the place called mixed grill. Go to the Plantation restaurant at the golf course...lunch here is great and the view spectacular. Do not take the Reef Dancer glass bottom boat....rip off. Book the pineapple tour it is awesome almost 6 years ago
Cheesburger in Paradise make awesome burgers - there's one in Lahaina and one in Wailea.
If you're around Kihei, stop by Fred's mexican for the margarita's and frosen daquiri's and get some nacho's. The rest of their menu is very average, but it's a cool restuarant with a great view of the ocean.
Don't miss Big Beach/Makena it's fantastic. And do the Molokini snorkel trip. You can get the boat from either Lahaina or Kihei depending on where you're staying.
Get up early (really early) and drive up to the top of Haleakala for sunrise. It is really beautiful, but freezing so dress warmly.
The ziplining is also great fun if you're into that sort of stuff.
Try www.gohawaii.com for more info almost 6 years ago
For a nice, relaxing lunch I'd recommend Hula Grill in Lahaina. They have a section called the Barefoot Grill where you can sit in the sand.
You should also check out snorkeling or diving at Molokini Crater and Turtle Town.
The road to Hana was amazing, but leave yourself a full day to get there and back. Also, bring a lot of patience because you can get stuck behind some real slow drivers at some points. To make the most of your trip rent a convertible or a Jeep. almost 6 years ago