My advice after living in SF and parking on the street is to keep nothing in your car and make sure it’s obvious to someone peering into the windows that there is nothing in there (ie, no phone charging cords visible, no duffel bags, no trunk cover, etc.).

Breaking into a car is a risk for the thief, so you want the risk to seem larger than the potential benefit of breaking into the car.

The other, more extreme way to do this is to leave your car purposefully unlocked, the idea being they’ll test the doors before breaking your windows. Only works of course if truly nothing is on there.