Has anyone on the forum tried to rewire the input side of the stock amp to split the signal that goes to the two front speakers so that it can be redirected to the rear speakers as well? The reason I'm asking is because as many of you know, the head unit's processing of stereo source material sucks, and the amount of sound coming from the rear speakers on stereo material is very low.

I was looking to do this by installing a double throw switch that could swap the input on the amp's rear channels to the input from the front channels, making the rear speakers effectively the same as the front speakers, and allowing for a better sound when listening to stereo material.

The question is, can this be done? Would it overload the head unit, or is the input impedance on the stock amp high enough that it wouldn't matter?

Any comments/suggestions?