If your Z has the automatic day/night rear view mirror, the easiest wiring may be right to it. I rang out the cable that feeds the connector which plugs into the rear view mirror. Pulling back the black sleeve exposes these three wires: orange stripe is always +12volts, black (no stripe) is ground, and red stripe is +12 volts when the ignition is on.
Hope this helps.

 

Thanks Phydoux I just finish installing my Passport 8500 detector from the day/night auto review mirror, beats routing that wire all over the place!

 

Just make sure that the mirror uses the same Amp fuse as the cig. lighter (15 A). Don't want to blow out your 8500 now! Well, I guess it wouldnt' be that bad.........then you could go out and get a Valentine One! j/k

 

i just did this, and now my dash has no lights. anyone know where the fuse is for the dash? the mirror looks like its dead too except the homelink still works.. weird! help!!

 

If your mirror is dead make sure your connections are fine, it might be intergrated with the dash lights(ya know Christmas lights, 1 bulb = the rest out). Make sure your splicing is good. Theres a fuse panel lower left kick panel, and theres another one outside under the hood under the battery panel. Should work I haven't had a problem.