Mike
I 've been going to the prehistorics for a few years now. It's without doubt the best free motorsport event you can see. I would say about 3/4 of the cars that attend the historics will be there. It's 2 days of practice for the competitors so you are able to see some great cars on the track. Also as there are no crowds, it's easier to talk to some of the owners. just drive straight into the padock and park, that's what i do! The only thing missing is the commercial side of the Historics.
Let me know if you decide to go, we could always meet up. I like to have lunch at the Baja Cantina!!!! A quick blast over the Laurel Grade.
Cheers
Matt