Can I wire my Radar detector with the normal 12V cord?
 

Im not very knowledgeable in wiring so i have no idea. I want to wire my Radar detector into my rear view mirror on my 06 G35. Can I use the 12V adapter cord it came with, Cut it and separate the positive and negative cords, attach an appropriate end on each cord, and just put it into the mirrors cord slots, like an invisi-cord does? The wires on the 12V are pretty tiny so im just wondering if they can take it.

If not, where could I wire it so that the cords hidden? thanks!

There's tons of room for cords behind the headliner. Just stuff 'em under there, run it through the a-pillar and down to the fuse box for a +12v switched power connection.