miniotto

I recently bought a 2015 Prius C 1 and I have a few questions that I hope you all could help with. I've been searching for answers to my questions, but I haven't been able to find anything useful so far. So I would greatly appreciate any help. First, is there wiring already in place to just remove the vent covers to add driving lights or does that require a new wiring harness to be added? Second, I have the basic four speaker arrangement to add the rear speakers, does it also have existing wiring or does that also require new wiring to be installed? Third, I would like to have more power to the audio can i just add an amp and a small bass speaker to the stock head unit? Forth, is changing the folding one piece rear seat to the 60/40 folding seat back just a simple swap or is it more involved? Also is there a factory cargo/security cover available? I was looking at the cargo area and I do not see any mounting points for one