I'm not there yet, but I want to put a 'dashcam' into my truck and DDs too.
I don't want the kind that sticks to the windshield or goes on the rear view mirror. I also want something that is discrete.
I've looked at what you will find if you search Amazon for "360 Degree Bird View Panorama System 4 Cameras 1080P Night Vision Car DVR", this one caught my eye...
https://www.amazon.ca/ASTSH-Degree-P.../dp/B07W8127HN 4 cameras, triggered by reverse, turns signals or a wireless remote. Does not include a screen.
If I found one with thousands of ratings I'd probably pull the trigger on one, for now I am waiting, this tech is in a period of rapid change.
In the hunt for compact cameras I also discovered what you will find if you search Amazon for "motorcycle dvr camera system".
For camera placement, my thoughts were:
Rear, inside drivers side box side top roll
Side, tucked up on box side under the top roll overhang, somewhere between fender and back of cab.
Front - this is tougher, I want it behind the swept by wiper area of windshield, but I don't want to look at the camera....still considering options
for a screen so it can be used as reverse or blind spot camera when driving, probably a drop down screen, either from a custom headliner or one of the screen built into sunvisor things
The bluetooth connected tablet as a screen might get you a distracted driving ticket around BC if they catch you poking at it.