After searching www.scca.com we have found the following info about the Runoffs:
SCCA’s information page for the Runoffs:
Parking/paddock/garage registration system
https://dk1xgl0d43mu1.cloudfront.net/user_files/scca/site_assets/000/028/367/original.pdf?1525374002
If you have any questions about this information, please contact the SCCA National Office. San Francisco Region is not involved in the management of the Runoffs and we are not able to help you sign up.