Spare harness in 370z trunk
 

I'm connecting the 4th brake light with reverse light and noticed 3 spare or unused harness plugs in hatch area drivers side under the foam for jack. Anyone now what there for and if I can tap into those for the lights ( parking, brake, and reverse lights ) don't what to tap into factory harness if I can buy a pigtail to plug into one of those unused harness plugs.

The FSM (link in my sig) will tell you what they are for. Possibly for the sub-woofer.

I'll look but I know the subwoofer plug as I have the bose sub :)