I didn't have one until you asked.
the back panel of the console pops off pulling it towards the back seat.
you will see I have drilled the hole for the socket low on the back panel and that's because there is crap above it that will hit when you put the panel back on the console, where I put the plug it will clear the console.
once you do all of that just splice into wires for the 12v socket inside the console next to the usb/aux.
here are some pictures if you decide to do it, I have a spare console on the bench upside down in some of the pictures to show you the wiring and fit of the plug when the back panel is on.