The upcoming dates and location can be found here (as well as other goings on):
http://www.socalcarculture.com/modelcars.html
I guess my info wasn't very accurate. It's actually in Buena Park (on Stanton Ave) and the show happens a couple of times a year. Don't let the name "kit collectors" fool you into thinking everything is high priced. If you're interested in kits other than car, all the better since there's plenty of armour and aircraft too.
Perhaps others, who have also gone to the show, will leave their impressions.