What kind of car you have? e90/92/93?
I would be more concerned on how water entered the car.
So far as the current condition is concerned, keep the windows rolled down little bit and park your car in sun for a few days. Being in CA, Sun is not a problem.
The smell will go away.
If possible keep the doors open when the car is parked under Sun.
This is really bad on the car wash's part that this happened and they did not dry it out completely or give you some sort of future complimentary washes.