@SMAlset , I left the car at the Sunnyvale SvC this morning. Got the same quote as you for repair. Apparently the small rear side window is glued in and cannot be replaced without also replacing all the brightwork (chrome trim) around the windows on that side of the car. Ugh.
The service advisor said that mine was about the 10th car to come in with its rear window broken into in the past 2 weeks. That's a car a day. Sure seems like an organized gang who knew what they were doing, and did it quickly with people around. Unfortunately no dashcam, and the business directly opposite my car did not have a camera.
Your observations about their methods seem like exactly what I saw. They broke the small window, flipped down the seat, and must have had a flashlight to look into the cargo area. Since it was empty, they moved on. I spoke to the owner of a Mercedes SUV which was parked a few stalls down; it had both its small rear and rear door windows smashed, because they saw a laptop bag in the back, and it got stolen.
Last time I had a window smashed like this, it was the '80s and stealing car stereos was a thing. Signs to "please don't break window" basically were an invitation for them to do so. I guess thieves can now assume there are other electronics to steal in a high-end car, and the percentage of cars with laptops in the trunk must be good enough to continue this spree. Hopefully the Bay Area PDs are taking note of the police reports getting filed.