The fronts in my 2004.5 Bose-equipped 5AT don't sound too bad now that they've broken in a little, but the rears are just awful. Others on this board have attributed part of the Bose system's problems to heavy-handed equalization, so I'm worried that this may not be an easy fix. Can I expect any significant improvement just by replacing the rear deck speakers with some good two-ways? Should I disconnect or replace the passenger speakers at the same time? Is it hopeless without replacing the Bose amp? If EQ is a big part of the problem, is it in the head, the amp, or both? (For now, I'm not necessarily looking for the ultimate solution, but I'd like to hear a significant improvement if I'm going to go through a lot of effort.) Your experience, please...