I have boston acoustic pro 6.5 separates in the front of my xterra wired to aftermarket amps. I wired the amps to the back of the radio where the stock amp is and tapped into the wires that go to each speaker to avoid running wires through the boots. I then put the crossovers in the door panel behind the speaker. I also put my crossovers in the door where the woofer is since the pillars are a terrible place for them in my opinion. I just unplugged the factory ones. The pillars do come off with enough force. Oh, and dont forget to unbolt the handles first