Welcome to MINI2
Unless things have changed, the only dealer in SoCal selling at MSRP is Long Beach MINI. You'll have to call them to see how long the wait is for a Cooper S ... it's about 12 months at the only NorCal dealer selling at MSRP.
To avoid the long MSRP wait, CA residents are buying out of state and shipping or driving their MINIs home.
All dealers should have demos you can test drive.