I have a 2007 g35x sedan with nav.. It comes with the rca audio and composite video jacks in the center console. There is a little tiny cutout where you can feed your wires out to use them for aux.. Its messy, ugly, annoying and impractical. So I did this..

first, I plugged in the rca (red and white) to 3.5 mm cable.. I ran it through the holes I have drilled in the back part of the inside of the center console (for the switches for the lights) and down past the air vent, under the center carpet and under the rear seat.
(dont worry, the infiniti logo is not attached there, I just have not put it on my front grill yet lol)



From there I used a 15 foot headphone extension to go out the driver side of the rear seat, under the door molding all the way to here





It comes out right next to the left vent where I attached a 20 dollar vent mount from radio shack.. this fits my droid perfectly!

I did this whole think for under 50 bucks..
mount-$20
rca to 3.5- $7 (amazon)
15 foot extension- $3.50 (amazon)

I also bought a new radar detector.. I had a cheap 80 dollar one which I wired into my rear view mirror.. I bought the beltronics v995 and did the same invisicord diy thing (safety pins soldered to the power and ground)

 

yay gadgets. Looks good my friend, I like the no wire radar setup

 

guessing you dont have bluetooth?

 

yeah I do, but It doesnt work with the droid.. I also use it for music..