Back in the late 80's, early 90's, I worked for a company that manufactured & tested
auto security & convenience devices. (Car Alarms, Starters, etc)
My personal security system was an "entry level" unit that I customized.
Most people will have an annoying (re: LOUD) siren in the engine compartment, (150 - 180dB)
but I chose a smaller 85dB unit. I added a time delay and "open relay circuit" to the output of the unit.
In a situation such as the one pictured here, after the window is broken, the door would be opened starting the time delay.
Generally, even with breaking a window, once inside the vehicle, the would be thief will close he door behind them.
Once inside, the approximately 6 second time delay would run down, the doors & windows would lock, the ignition interrupted,
and the 210dB siren mounted UNDER THE DASH would start sounding.
"No Officer,I didn't see who broke into my car.... but he/they should be easy to find.....
they're the one's with the blood coming out of their ears."

BTW... the "open relay circuit" is designed without a "return", so once the relay is triggered, the only way to turn off
the painfully loud under dash siren was with the alarm systems remote control.
