Yesterday, installed the new Head unit, amp and door speakers. Also ran the wiring to the rear sound-bar speakers, and it all works nicely. Amp is under the drivers seat, had to raise the rear of the seat around 15mm so that the seat adjuster clears the amp.
RCA's are to the rear of the vehicle, and go straight to the trans tunnel where they run under the carpet. Have another RCA to go to the rear where the sub and mono-block amp will be. Door speakers have 2x 18mm spacers bolted to them so they fit, and the rears will have 1x 18mm spacer to help reinforce the soundbar a bit. Sounds good already, but should be awesome once the sub is in too.