Yea there is info on the SCCA site or go here: http:/http://www.calclubrallyx.com/
Glen Helen is set up in a big not-quite-flat dirt lot at the motox track and Johnson Valley is on a lake bed. Glen Helen is fun and slippy and any stock height or slightly lowered car would be fine. But Johnson Valley is cool cuz the surface is almost like concrete but you obviously slide more cuz it's dirt. Even low cars are totally fine at Johnson Valley. They're not super close to San Diego, but not too bad. And as far as I know they're the only organized rallyx in SoCal.
I may bring out my rally car to some of these if I'm not busy with stage rallies.