2005 rear speakers

2005-2006 do not have to remove all panels to access the rear speakers, just pop the grill off. Getting a screwdrive back there to take them out is a pain, but assuming you amp the speakers, it's totally worth it.

The factory speakers in the rear run at 15 watts a piece. They are super sensitive non-pressed paper cones. If you replace them without adding an external amp, they won't play as loud as the rest of the speakers. Also, if you replace the factory door 8" woofers, be careful. I've seen kits that say the just go right in, but when I replaced mine, it took a little bit of modification to keep it behind the factory grille. Also, adding any extra bass to the doors will make them rattle, so be prepared to sound deaden it, it took 5 layers per door for me, but I ran actual subwoofers, not midbass woofers.

The shaker500 is really only an amp that powers the two door woofers. I was so disappointed when I pulled out the stock 6x8s and they were paper and had "15 watts" stamped on the bottom... And with the kickers, I'm sure they will sound good, but if you want it to sound BETTER than stock OR to sound as good as they possibly can, you definitely want to amp them. I replaced everything in my shaker500 with Rockford Fosgate power series stuff and added two RF Power series 10s and it sounds amazing. Granted, I am running 2,800 watts RMS to everything, but even just a small amp should sound WAY better than just what the HU will do. These new mustangs have great imaging with the 6x8s high in the front doors, so either way you go, you'll love the results!