On my car basically avoided the wiring and ordered a extra long 12v cord on ran it neatly to the armrest,the best way for you is maybe removing the light panel by the sunroof,you will have access to the wires from there,correct me if i'm wrong.
I did get a big 12ft power cord, I may just run it down the windshield pillar and to the console. But I did get the hardwire kit too. I want the detector to go off when I turn the car off. What port did you use on the fuse box pokermunkee?