Often for trial and testing purposes, or other situations where we cannot permanently hard-wire a device into a vehicle, we need other alternatives.
Digital Matter manufactures an OBDII and cigarette lighter harness for the Dart3. However none is available for the G120 (due to limited demand)
For such scenarios, it is easiest to simply connect the power (red) and GND (black) wires of the G120 harness to a cigarette lighter plug such as the following:
https://www.jaycar.com.au/cigarette-lighter-cable-with-bare-ends/p/PP1995
This conveniently has 2 bare ends for quick and simple wiring (make sure to insulate your connections to avoid any shorts)