Audio Wiring

So, I am a little confused about the wiring in my Spec. I went to Circuit City to have them install my new Infinity Kappa components in my doors. From experience with the install of the rear, I knew that the wiring in the car is like 20 or 22 gauge. So, I picked up some 16 gauge wire and asked them to install it.

Guess what they found out... the front is already set up with 16 gauge wire!

I can't figure that out... why would the front be 16 and the rear 22.

That is really bizarre... Can anyone else confirm the same observation, or explain reasoning?

Anyhow, I now have Kappa coaxials in the back and components in the front. They are amazing... even off a 44x4 W Kenwood deck that probably only puts out about 12RMS. I can't wait to get an amp in there.

Has anybody installed an amp yet? I am wondering about where to run the power cable through the firewall? I heard there is a hole behind the glove box in another forum, but I can't find it. Do you need a special adaptor to hook up the power to the battery, or does it just attach easily? Do you need a fuse in the engine compartment, or can it be anywhere?
Are their any tricks to pulling off certain body panels to run the wiring back to the trunk? If anyone has done an amp install, and would be willing to share their experience... I would appreciate it.

Thanks
GB Phoenix77