hawaiimoon05: what a great report! We are going to Maui and the Big Island this fall for 10 days total (5 and 5), and are planning on doing many of the things you did - Haleakala crater (driving up on our own), the Old Lahaina Luau, Mama's Fish House, Four Winds II, Pahu i'a, the volcano, Mauna Kea summit (also on our own and going only to the visitor center)
I e-mailed your report to myself for future reference. thank you

About the Mauna Kea summit -- we rented a 4WD (Thrifty offered us a deal on the upgrade) and drove up to the summit. Not too hard or scary, and I scare easily when it comes to driving. There was one couple that went up in a regular 2WD compact rental car. They had to go really slow, but they made it up and down in one piece. It is even colder at the summit. It's neat to see all the obervatories up close, although the evening we went, the sunset was nothing spectacular. Still, the stargazing was awesome. And we saw Saturn and Jupiter through the telescopes. It was completely unreal.