i dunno how long you've had your car, but at a guess would say you have stinky a/c gas... take it to an a/c place and they will recharge it, and deoderise it too....
other wise i'd say you probably have water in your car... being in CA will work to your advantage, either leave your windows open a crack in the sun all day, or if you can actually leave the doors open all day or at least a few hours....