Here's what I would do:
Monday - pick up the car, grab dinner on the way to the resort, and and watch the sunset from the beach. Jet lag will probably hit hard this day.
Tuesday - Relax in the morning, then take a drive up to the North Shore around lunch time. Take the highway straight up the island to Haleiwa. Watch some surfers at Pipeline, find a place for lunch, and get shaved ice at Matsumoto's. Go to Kawela Bay Beach Park for the most secluded, perfect beach I've ever seen. The Cultural Center and Pillbox hike are near this area too. Grab an acai bowl, iced coffee, or smoothie from the Sunrise Shack as some point during the day. Make sure you leave for Aulani before sunset, because traffic on the North Shore gets bad when everyone is returning to the city.
Wednesday - Wake up early to do Pearl Harbor and the Diamond Head area, including any hikes you feel like doing. Stop at Leonards for Malasadas, since they have more flavors at the main building than the truck near Aulani, and see Waikiki if you're interested (not my favorite, but they have high end shopping). Get back to Aulani at a decent time to enjoy the pools and beach.
Thursday - Enjoy the resort all day. If you have the energy for a long but flat hike, Ka'Ena Point is the northwest point of the island and an animal sanctuary
This is the best advice I’ve read so far, in that it offers a chance to see some nice sights while still providing an opportunity to enjoy Aulani. And it’s doable! With weekday traffic, I don’t think its a good idea to plan wildly ambitious days in an attempt to cram a week’s worth of sightseeing into two days. That could be a recipe for just sitting in one’s car for hours in one traffic jam after another.
