I would not connect directly to the battery, use switched power.
You can do your own cabling starting from the option socket behind the instrument cluster: 12V + GPS power; in this case you only need the OEM connector (https://ruggedroads.co.uk/4-Way-OEM-...roof-Connector
) and then you do the cabling (you'll also need a generic 12V socket).
Or you can install "OEM way", buying the 12V socket kit and the "sub harness kit" (Y cable) which will allow to power a second accessory (GPS). In this case you still need an OEM 4-way connector if you want a "clean" cabling (or you'll cut the Y cable and connect directly the GPS power wires).