I added a (sort of) security system to our 2023 320. I bought a 12V dusk-to-dawn motion sensor LED light and mounted it low by the door handle (so as not to light up the entire campground if it goes off).
This is what it looks like at night when it triggers by motion after dark:

Here is a video of me triggering the motion detector (red LED indicator is also visible):
Just above the light, and separately, I mounted a tiny red LED and wired it to a 12V "blinker/flasher" to set the sequence timing. This blinks continuously (for no other reason) to signify that there is a "system" installed.


A video of it in the daylight here:
Lastly, I connected both of these to a new switch on my 12V panel - the "Zombie" switch. We just click it on when we want to be "protected"