Hi hext
I havent fitted one yet but making a cubby with switches on instead of the dash so had a god look around, myn's older but it seems they dont change much.
Battery off
Get yaself a coat hanger and cover the end in tape with abit of a buldge so you dont damage anything.
Take of the fuse box cover.
At the top of the box theres an opening that will go upto the dash area where the wires come out in the centre, ya may have to take your head unt off depending on location)
now you can do the old attach a wire to the hanger and pull it through, i was planning on putting my smaller (10amp -) wires just over by gearbox but under the thick rubber cover in some heat shrink, bigger wires i have put a small sealed whole into the top of the gearbox tunnel and then run that along and up to where the bulkhead is (my larger power cables come up through a sealed aread there).
that should allow power to come from bat, earth from bat and depending on sub model Aux leads from headunit or back left and right speaker wires. just grab some cable tubing for your cables underneath, if the tubing is sealed i.e. not split along then just push them through and silicone each end, if its split i put a blog of silicon inside and a couple of inches spacing to the hold it all together and the wires in place (soz if you knew all that already).
As for scotia and crowmann. cant even be bothed with ya.