Really have no idea where else you can plug one in besides the port as that's usually what most people does.
Mine is also running with this same wire kit. Makes for a clean set up. Up and out of the way, hardly know it's there.Just got a radar jumper wire that I hooked up to the mirror wiring. Very clean.
https://www.amazon.com/gp/product/B00RA38XEK/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1