They just opened up sign ups for the GG Lotus Club at Thunderhill (backwards) on Sept 10th. You don’t need a Lotus to sign up, see http://gglotus.motorsportreg.com/
If you can swing a Wednesday at ThunderHill, this is easily one of the cheapest $$$ per minute seat time events you can do in Norcal. It’s $165 for the day ($145 if you’re a club member). They have a 3 run group format with 20 minute sessions. When you sign up, you sign up for Advanced/Intermediate or Intermediate/Beginner. The beauty of this system is that you can drive in 2 groups if you’d like (40minutes per hour). Intermediate requires point bys, Advanced is open passing. The club is super laid back, and you get to pick on Lotus Elises 
The events usually fill up since they cap it at 50 cars total, so sign up sooner rather than later.
I’ll be out of town for most of September, else I’d definitely be there.