Adding a tube.. easiest way to install

To start out I have a 2012 Prius 4 with the Green Edge system.

This has been asked before, but in all my reading I couldn't get all the info I needed.
I got one of the smaller 8" ones with the fast connection so I don't need a 12V from the battery.

Where is the easiest place to tap the wires?
Should I just tap them at the amp under the seat, or is it easier to just pull the HU and tap everything there?
Many people have said they tap the speaker connections at the amp, but I need the constant 12V and the remote on wire.
If I have to go to the HU for these 2 I might as well tap them all there.

Thank you for any help, and yes I know I could Google, and I did, but no one really ever spelled that out.
I know there are quite a few people that run these so any input would be greatly appreciated.

 

O.k. I am stuck...dash is torn apart, ready to tap into the head unit and there is no blue wire.. I see the light green, violet (purple) and the pink on one plug.
I see the light blue and grey on another plug for my 12V and ACC but there is no blue wire on the plug with the rest of the speaker connects?
What wire am I supposed to be tapping into... Prius IV with Green JBL?

Appreciate any help.

 

I would have no problems paying the $15 but I have seen the diagrams from everyone else, and according to the diagrams which aren't the easiest to read anyway.. it should be violet, pink / light green, blue/ and grey ACC light blue 12V.
But I have no blue wires on the back of my HU... I can find it on the amp under the seat... but then I don't know which wires for ACC and 12V

 

Got them from here on the site, but none said if they were the green system exactly.
They are the really kind of confusing ones to read.
And of course every picture of the JBL amp has 3 plugs, but guess what mine only has 2 plugs lol, one small and one really big one.

 

Ok paid for the subscription and it is in fact the same ones I found here... only question would be if the wire is supposed to be a different color... on the diagram it says Front RH is LG and L .... all references on other years etc. have been Light Green and Blue for the L if it's supposed to be something else please call me an idiot and clear it up for me.

 

Haha can someone please confirm that the wires I need to tap into actually don't unplug from the HU?
I mean you can unplug them but you don't have to if you want to remove the HU from the dash.
I was starting to put things back together, and I looked at the harness that connects the lower part of the deck to the upper part and there is all the wires I need.
I never looked at the back of the unit, just the connections I had to unplug to remove the deck.
Someone please confirm this for me...
And thanks.....what an idiot I am