When I enquired at Kawasaki about an OEM power outlet they said $210, I think because you need a power relay as well to light up the 300's accessory wiring.
Instead I went to an electronics store downunder called Jaycar (do you still have Tandy's) and bought a marine suitable outlet for $6.95.
I then probed with a meter and found switched wiring to the tail light. Australian regulations require hard wired head/tail lights.
The tail light plug is pictured below below. Red is power, Black/yellow stripe is earth. I used those crimp on splicers to avoid soldering or cutting at circle A. the other half of the plug is B.
Here is the finished connection with the blue splicing units tucked out of the way and with the plug reconnected.
Here is the plug in place. The hole was just a little tight so I opened it up a tad with a rat tail file. Note the second connection. I twisted the red and white wires from the tail light with the red and black wires from half of a SAE bullet type connector and soldered both pairs into the plugs that connect onto the power outlet. $3.45.
I will use the other half of the bullet connector, soldered to a wire-in 12v to 5v adaptor to mini USB ($19.95) which will be permanently wired to my fixed Mobius camera.