There is a plug under the seat for the OEM power add on in the glove box. I would use that since it's meant to be the acc and is power switched.
The Honda "cigarette lighter plug" that goes under the seat is WAY overpriced ($80 or so)
and only handles three or four amps... but I got it anyway, plug-and-play man

I bought a plug from Amazon and modified it so that it supplied power to a relay,
and that's how I trigger the heated gear circuit.
I have a GPS

and I have a splitter plug that will turn my one "cigarette light plug"
into two... then my three (four?) amp Accessory plug will be driving a relay for the
heated gear and the GPS...
-Mike "and no spliced wires

"