If there is a canbus adapter, that's good. But I was thinking possibilities to remain undetected by the car systems. If the dashcam is powered from the same fuse as 12 V accessory outlet there is no way the system knows if it's the dashcam or some device plugged in to the outlet.
+1
I agree, the Canbus system, has 'nodes' that control individual bits of equipment that communicate with the controller modules via a two core bus cable, the power can be supplied in same cable ( 4 core with two heavier power conductors and two light data cores ) or a separate cable. If you plug something into 12v power that comes from battery and not via the controller the system will not know what is plugged in as there is no data cable to controller from the device. CAN bus compatible on LED bulbs purely means that the LED has to draw the same current as the filament bulb it replaces or the node supplying the bulb will see too little current and think bulb has blown, - normally a resistor in parallel with LED does the trick, some LED bulbs sold as CANbus compatible have a resistor built in.
LED bulbs have constant current power supplies built in ( LED works on current not voltage ) some cheaper LED bulbs without filters can introduce interference into the system though, which may affect CANbus data transfer, so some CANbus compatible bulbs can have extra filtering in them as well as a resistor.
Interesting piece
http://blog.ecobd2.com/tech-support/automotive-can-bus-system-explained-instruction-diagnosis/
I remember my old Clio wirings...
Black wire = earth or negative pole.
Red wire = +12v directly connected to battery
Yellow wire = +12v aftet ignition
Couple of crossed wires = CAN-H and CAN-L data cables.
I found a TPMS ECU for Renault Clio, put it under the passenger seat and made a power+data cable with a sort of rj45 plug to connect it with the car: cut and solder black and yellow wire, cut and solder two other cables from a couple of crossed can cables. After a reconfiguration, it worked fine...
To me it's strange to hear that in new cars power cables are electrically checked by canbus: surely if you touch a canbus data cable the car will show lots of alarms, but +12v cables, mmmhhh.