i have infinity reference model in my car they sound damn good for being budget front and rear stage. I have also heard the polks in a buddies car they do sound damn good if those are what your getting i would personally do the polks up front and infinity in the back but you do not need two sets of components most people either run just midbass or coax in the back because its all about staging you being the driver want the best sound stage where your sitting. In a build i just did recently we did a set of rainbow components($300) amped on 4channel with just midbass drivers(cdt) in the back also amped of the 4 channel and 2 IDQ10's sounds great..... So here is the question what do you listen to because that should honestly help decide what you get. For love of all that is good do not by kicker subs pls lol.... subs i would recommend that i have personally used and heard that have a very accurate reproduction of bass would Imagedynamics done 2 builds with IDQs and ID series and both sound phenomenal and they don't need a lot of room. My personal favorite was the Tc sound epic 12 that my buddy has it just sounded amazing in 1 cube box... just remember for subs it honestly ways heavily on your box, you can have the most expensive subs in the would in the wrong box sounds like ****. also about the 5 channel depending on the subs you might just want to get a 4 channel for the speakers and mono block class d for the sub.
Farad do not worry about it( i kinda think its a gimmick)
Wiring contingent on what subs/amps you get and the load
and if you order your head unit from crutchfield or sonicelectronix they usually come with everything you need just make sure it says it comes with installation accsesorys.
Here is the build we did on my buddys 05 Rsx with 2 ID 10s and boston acoustic s65 door speakers. 05 RSX Build
and also here is the build we did in my buddys 05 mazda 3 he got the IDQs and other fun stuff i listed above. 05 Mazda 3 build
We actually just re did his box about a week ago because he wanted to try a smaller box his new box is 2.3 cubes witch give him his trunk back and still sounds amazing in my opinion ill try and get some pics up of the new box if your interested.
