To each his own, but I would like to throw in an opinion on the above. In my experience, rear speakers are a waste, in general, but most especially if you are building the sound for yourself. They usually do nothing more than muddy and confuse the sound stage.
Also, I NEVER recommend installing resistors with speakers. Not only do you have to install one with the proper power rating (depending on how much power, these resistors can be very large in physical size) but you are also wasting power that you have already paid money for. Just doesn't make sense, in my honest opinion.
Again, certainly don't mean to be argumentative, and of course anyone is free to do whatever they choose. I just wanted to throw my two cents out there, in case it may assist anyone.
By the way, the Mustang above sounds awesome!! Very nice!
Yeah... Don't know who's it is but ran across that clip and figured it applied to a thread about putting money into sound, on a Mustang.