I'm just finalizing my 4-wheel drive car rental and was informed to not even think of driving up to Mauna Kea (part of my reason for having this kind of car) because it's crossing "military land" and the rental car companies have agreed to keep this road clear of "tourists" traveling independent of a tour group. I was told if I defied this understanding, it could impact my rental contract. I was told that the only way to go up to even the lower elevation Visitor Information Station was with a tour. Well I've got kids and I know these tours are expensive. Is this a bunch of hogwash? I'm a very independent traveler, and I'm having a hard time buying this story. Please give me your thoughts.