Hey guys, We rented a Jeep Wrangler and there was no rules about where you could drive.
Tours will pick you up around 11am, take you to the visitor centre, then take you up top for the sunset, then back down and then home. However you don't get to go INTO an observatory.
On Saturdays!!!! Take a rental up there. Get to the Visitor Info centre before 1pm, and you will get a free tour led by the uni. They will take you INTO the Keck!

Then you stay for the sunset, and head back down. You can do this in your hired 4WD. Must take a 4WD!