Most absurd use of SS: Vehicle camera platform

I often push SS to the edges of where & how it should be used, so this post may be yet another case of that.

Recently, I've had a bit of frustration trying to find a decent vehicle camera. They're all pretty inflexible from a programmatic point of view, and the cameras are clunky, obvious, and not very feature-ful. I've looked at setting up a Raspberry Pi with cameras connected to it, but that goes a bit too far in the other direction - I am not looking for something that I have to write code to make work or mess with building my own hardware.

While it may be an abuse of my (spare) battery in the vehicle, I think I can get SS to work as the core of this project. I can make it power down after a set interval, and a combination of some solid state drives and a reasonable system tucked into the spare tire well should work just fine. I can set the Mac up as a wifi access point, and use WiFi cameras.

My problem: cameras. I want something that is nearly invisible, and cheap enough that I can have four or five of them scattered around the vehicle. I know SS is a motion-detecting system, so this is probably not a fabulous match of features-to-functionality, but I know the system really well and it would suffice even if it's storing full motion for much of the time.

I've seen a huge number of really really cheap "spy cams" on AliExpress that have really great physical form factors and would work well in a vehicle, but none of them support ONVIF and they look super-sketchy. "AVI" seems to be the encoding method most used - I'm guessing that is not workable. However, the size and camera heads are perfect - a matchbox-sized transmitter box, a long thin cable, and then a tiny camera head that can do 4k. These would fit very well in the headliner, in modified turn signals, or in discreet forward/backwards camera mount blocks that I could 3D print. All I would need to do is run a single power wire to them with a buck converter for a mini-USB format power input, and some even have batteries.

Does anyone have any experience with these tiny cameras? Are any close-enough-to-spec that they can be made to speak RTSP with a usable format? Are there any codebases that I haven't had the right keyword searched to find that will convert the garbage format to a digestible RTSP stream on localhost?

The "buy one and experiment" model is appealing, but I suspect that the vast majority won't work, so even at $20USD that isn't an option, and I don't have unlimited time. Hoping someone might have direct hands-on experience with some of these that can weigh in.

Research background: I found these (Italian) which are too big: https://www.dsecctv.com/Prod_mini_telecamere_wifi_nascoste_onvif_miniaturizzate.htm

And Axis has a few cameras which are just too high priced and the camera head is still too large.

There is the possibility of using the ESP32 cameras (https://www.arducam.com/esp32-machine-vision-learning-guide/) since someone made an RTSP converter (https://github.com/rzeldent/esp32cam-rtsp) for them. This is still not particularly sleek, the word "soldering" is used in the docs, and starts to sound like a lot more effort to implement.

Example AliExpress camera: https://www.aliexpress.us/item/3256803214758663.html