I'm looking to add a aftermarket amp and subwoofer to my trailblazer. I need to access the rear speaker wires for my high level input converter and I'm wondering where would be the easiest access? I looked at taking out the factory head unit and it looks like a lot of steps just to find the rear speaker wires. I was thinking of maybe tapping into the wires right where they pass through to the door but wanted to see if anyone else has found an easier way first? Any help is greatly appreciated.