My guess is your dash cam will be 5v, powered by a USB adapter this would normally plug into your lighter socket. I have built a dedicated USB system into the car where I can pick up power for the various devices I use (don’t ask).
I wouldn’t expect you to follow my route, but a simplified version could be adopted.
My camera is mounted next to the rear view mirror on the passenger side & my nearest USB outlet is in the footwell fuse box. I popped off the trim up the A post & over the windscreen & ran it around there, a cutout being made for the cable to exit. I use the fag lighter circuit to run the main USB sockets for when the ignition is on & an “auxiliary auxiliary,”which is powered constantly.
The DLR system has to be dependent on your kit. I was an early adopter of these systems, designing & building my own, which is crude in comparison to the modern offerings, it has been reliable & I’ve no intentions of changing this basic system, however I have supplemented the system with wing mirror mounted white light, which act as indicator repeaters.
The repeaters on the front wing are of little value these days as most vehicles one comes across have wing mirror repeaters & who now noticed an inch square orange lights lamely blinking when everyone else has “startlingly loud 150db” lights.
There are so many options with stuff like this & it all depends on how confident you are with car electrics/electronics, I’m in & out of this stuff almost daily to the point where I can look at wire colours & tracers to identify circuit families if not actual functions.
But there again I’m a bit odd.
M