Hahahahhahahhahahaha.
Seriously, Lol. You guys.
If you're using a head units power, I guess stock wiring makes sense... but feeding 50W+ RMS from an actual amp through factory wiring? WTF for? It's not that much more work to run the wire, and who can't afford 50ft of 14ga? I'll pay the extra $25 and put in the extra hour to get that last bit of dynamic range out of my components, which play some 80% of the music anyway.
Cmon guys. Don't build systems/make decisions you'd be embarassed to tell your local car audio shops/installation gurus about.