An easy solution thats comparable to you using a hardwire dashcam cable for your Gnet dashcam only this is literally plug and play.
 
You can easily plug this Plug&Play OBD power supply into the OBD plug of the car (please ensure you have an OBD port, this is normally located in the drivers footwell of your vehicle).
 
Your Gnet dashcam is then supplied with power and will also automatically switch on and off. The OBD power supply is equipped with a low-voltage cut-off system where it interrupts the power when the voltage of the battery drops below 11.8V but if you leave your car for extended period of time you can simply unplug the connector.