2015 radio rear speakers

OK, I searched around for a bit, but I couldn't seem to find anything.

I'm just trying to install rear speakers into my grandpa's Tacoma for him. It's a two door, two seater 4 cyl awd. I don't know how much of that is relevant. I do car audio all the time, and he took it to the dealer to ask them how much it would be, and they said something outrageous, and he got pissed, so I'm gonna do it for him. The head unit is the basic touch screen it seems, I have no way of telling whether its non jbl, endure, but it has no steering wheel controls, no nav. Supports idevices and has aux in.

There's just no rear speakers, I'm not even sure if the harness has the necessary pins for the rear speakers but the radio has fader and such. I'll makeshift my own pins for the harness if I need to, so all I really need is a pinout of the harness. Or wiring diagram if the pins and wires should be there already.

If anyone could help me identify the radio and or point me toward a pinout I'd be greatful

 

Woah. You just blew my mind, rock lobster. Would the head unit handle the change in impedance if I just spliced them in, and would that affect the exciters?

 

And if not, how much worse would it sound if I just cut them so I don't have to explain what headliner exciters are to my grandfather.

 

also its the single cab, not access

 

Didn't even know they sold that anymore...lol

Just wondering why you want to install rear speakers? If it were me, I'd think I'd replace the door speakers, and add a small sub under the seat.

 

Exactly, don't need no rear speakers! invest in the front and set it up right

 

My grandpa was an audiophile in the 70's.

He keeps saying the term quadraphonic

He just wants rear speaks man

 

Also the sub is a no-go, bass makes him all ptsd and makes his ears feel weird

 

Christ how old is he? I'm almost 60, and can't understand his position.

 

https://en.wikipedia.org/wiki/Stereo_Quadraphonic