You make a good point. Definitely easier to correct timing when a single listener is involved (and stationary)

Now, for the sake of argument, lets dumb it down a little bit. Lets say this..... H20Doc's favorite band of all time (hansen) Lol is coming to his house to play For his birthday.
Take away the electronics, the amplifiers and the speakers, ect.
You sit on your couch, as they begin to play, and the sound is perfect, crystal clear, as You start to slip away into a music induced euphoria are there 3 brothers in front of you, or 2, with one (gasp) behind you?
Who wants one of the Hansen brothers behind them when they have lost all motor functions? Certainly not me.

Disclaimer: This post was in no way intentionally insulting to H20Doc or the Hansen brothers, and is the sole property of its poster. No persons or animals were harmed in the making of this post.Reproduction is a crime, and will result in prosecution of the offender.

I only like Hansen because I was boning the hot chick for a while.

@jsmith7861
Take a look at this post, could lend you some really good information. H2O and BigAudio are great references to look at on the posts here to get an handle on how you wanna proceed with audio. I like many don't feel the rears are worth the time, or the effort to wire in. I have just updated my build to be shipped as follows:

In Dash - Pioneer AVIC X930BT
Doors - Infinity Kappa 6 1/2" Component System with 1" Tweeters to go in the Door Sail Triangles.
Dash Tweeter Delete
Kicker SoloBaric L5 or L7 in the back
Not sure on AMP at this time, but something digital - Monoblock to power the Subwoofer, and probably a Xtant or PPI or Soundstream ( 3 major contenders for 4 Channel I'm looking at) for the Components.

Here's the link and Good Luck! Welcome to the forums! (PS Scroll to the 4th post which i think is mine)

Mooshu's Post and Osirus's Summation

^for the price, the Kappas are some of the best speakers I have heard. Tuning is important as they can be quite bright, but in that brightness is where you get a lot of the details and subtleness of music; you get comments like "I am hearing things I never heard before..." from many first time users.

Caveat: I have never owned super high end speakers before, so my knowledge is limited.

@H20_Doc, I have had MB Quart, Kicker, Boston Acoustics, and many OEM Factory builds as well, and for the money and proper tuning and amp powering, Kappa's to me have been my bread and butter go to everytime. Seems like with all those things tied in, you get an amazing reproduction of mid and slight low end, however the Highs and that sound is just impeccable. There just comes a fullness that you can't get with many other components IMO. I was in my earlier years a Mobile Installer at a prominent Yellow Box store, in which we featured Magnolia Hi-End as well. This allowed me to finally audibly sample the differences in equipment, which then allowed me to tailor my opinions of what the acoustic footprint in many vehicles could best benefit from which types and brands.
Hope this helps.. To the OP Feel free to reach out to all these great guys in Audiophile reference.

There is not, you will have to run your own and install the pins into the factory harness to allow the signal to be sent from the head unit. Or you can install a new head unit and it will be pre wired for rears. My recommendation though it to install new front speakers (components) and possibly a new head unit before installing rear speakers.

Ron I am completely with you to listen to music HOW IT WAS RECORDED with no rear fill.

Car audio is different from all other forms in terms of listening environment and ultimately it is a preference BUT there are merits to rear fill addition to a system although I prefer NOT to have it in my own system and have never designed one with it. That said there are legitimate reasons for it, namely psychoacoustics, time delays and phrasing issues caused by the car interior and the many differing acoustic properties of materials found in a car.

Since we are dealing with recorded materials, unless you drive the MClaren F1, there is no way to address the off center set up in a typical car so you end up not being in the sweet spot and also dealing with timing issues. Add that to placement of a component set up and it's progressively more problematic. Now figure in all the differing materials and you have even more problems causing all sorts of phrasing issues. So why more of it by adding rears? It is to compensate for these particular issues. Is it 'sonically or musically' more accurate? No in theory but psycoacoustically, it is can be more pleasing and can be more 'accurate' - IF DONE RIGHT. Which is why OEM especially high end system have it. It works because they have the tools and the research to tailor the setup to address these issues using built in processing/drivers while tailoring to specific cars and trims. Something that is really impractical for the aftermarket to do. All that said, is it likely better to NOT do it. Yes a good set up and better install will not need rears but if it sound good to you, go ahead.

It always bugs me that people are so adamant about what to use and what not to when making recommendations in particularly speakers but don't take into consideration of people's own preferences and musical taste. I remembered listening to a set of Wilson Audio Alexia at booth and a guy came by and said "my cerwin vegas D-9 sounds better than that ****"... He was right if you were listening to AC/DC and certainly to him, it did.

Add a Processor.

to address the driver's or the passenger's placement?

I just drive around leaning forward and to the right a bit.

Processor in the P99 has a setting for L/R or Both, and works rather well.
There are many cars in meca and iasca that run 2 seat SQ.

:icon18:

When its just me, its set L, when I have a passenger, its set Both. All in the press of a button.