It looks to be run under SCCA rules, though not necessarily an SCCA sanction. Ridealongs will probably depend on the insurance underwriter of whomever IS sanctioning the event (CMP or Subaru). Some places, like our SCCA region, allow ridealongs for anyone that has signed the insurance waiver. Others require a rider to be a registered competitor to be covered by insurance.
Hopefully Josh can clarify soon. If not, I will beat him brutally at the AutoX on the 16th and make him come post here