Can't find how to set up a 4 channel amp w/ aftermarket HU
 

I'm not sure if it's been discussed already, but I have a MA M500XE 4 channel amp that I want to run my stock Bose speakers with a kenwood DNX 5160 HU with. I have the stock Bose amp in a 03 sedan, I'm not sure where to tap into the speaker wires and what needs to to be disconnected so I don't blow anything up... I read how to bypass the stock Bose amp with the stock Bose HU but didn't make sense to me. Any help or direction to a DIY would be much appreciated...

It's in the sticky section within the thread you just posted.

The wire colors with diagrams?

I'm not keeping the stock HU i already upgraded to double din

Wrathernauts double din install guide. It talks about everything you will need. As for the amp, any YouTube hit will show you the basics there. The Bose amp you are going to replace is a nice spot for the new amp.

I know how to wire an amp I'm just not sure where to tap into the speaker wires, before the stock Bose amp (wiring behind the HU) or after the stock Bose amp (wires coming out of stock amp under the rear back seat shelf) I know I have to run the power, ground, RCA and remote lines. I've already wired a sub with a separate amp

Seek and ye shall find.

Anybody else that can help?

I'm pretty sure the oem bose speakers are 2ohm so unless youre changing the speakers as well or the amp is 2ohm stable in 4channel mode I would recommend just leaving it as is. if you do change the speakers then bypass the oem bose amp in the trunk. you gotta look for the wiring color diagram though. just run RCA's from the front to the amp, then connect speaker wires from the amp to the harness at the bose amp(bose amp unplugged of course) according to the color diagram.

It's 2ohm stable here's the specs
Power Specifications - Full Range Channels
RMS Power @ 4 ohms125 watts x 4 channels
RMS Power @ 2 ohms225 watts x 4 channels
RMS Power @ 1 ohmNot Stable
Bridged RMS Power500 watts x 2 channels
Peak Power Output1000 watts

Thanks JDM-V35 that answers my question I think