Lived in the Bay Area for over two decades. Yeah, leaving a visible item in your car is just bait for the smash-and-grab crowd.
It sucks but once you know it, it would be like thinking you can just leave your wallet sitting on a counter.
For what it's worth, everything was in a locked truck with no visible way of seeing any items.
From what I heard from others, apparently the thieves have a device that allows them to detect electronics (I had two laptops, cellphone, and a few other devices). I'm not sure how accurate this is, but i'm not sure why my car was the only one on the street that was targeted as there were no visible signs of valuables in the car (nothing visible from windows etc.) Funny part is a few weeks later nothing was found except for my Kindle which a kind citizen found and returned to me. Apparently thieves don't like to read?
You can also do that in high-functioning societies. In Japan people leave their purses, phones, etc to hold their seat before ordering in a café, going to the bathroom, etc.