Too Large of wiring, Possible?

I don't believe you can go too large on wire size.  The amplifier only draws what it needs so larger wire would make it a lot easier on the amplifier.  If the wire has the capability to carry more amps than what the amplifier needs, then the amplifier will only pull what it needs and not the extra.  I hope that wasn't confusing.

There is no such thing as overkill when it comes to car audio!!!! However, there is a logical limit where adding an extra strand or thousand strands to a certain gauge no longer makes a noticable difference or practical sense. Don't forget to beef up the OEM grounds to match the B+ harness - an unfortunate oversite by many.

Re-read your MECP studies where they explain voltage drop and relationships between conductor diameter/length/resistance.

The only instance I can think of where wire guage can be too big is high frequency signals. Higher than you will ever see in car audio.

What are you talking about?

The only instance I can think of where wire guage can be too big is high frequency signals. Higher than you will ever see in car audio.

please, explain.

When the cross section of the conductor is significantly larger than the wavelength the signal can travel back and forth across the wire and double back on itself causing attenuation. Like standing waves in an enclosure but with much smaller wiggles. But you have to get into the gigahertz to get that effect.