The calendar shows classes available for New Owners Track Drive (NOTD), and I asked a (the?) phone rep whether the availability is accurate for NOTD and she said that it was, but you can't book through the website.
https://pds.eventsbmw.com/?brand=BMW&date=2024-06-01
Clear the filters on the calendar, then tick the options for Thermal, CA and "New Owner's Track Drive". You can view availability for upcoming days at the Cali location. For example, they show 20 spots on 9/27/2024 and October 11th has 10 spots remaining.