I agree. When I installed my stereo on my former Caprice I ran it from the battery over the passenger side front fender down to the frame. Then I fed it up into the body/frame gap all the way to the rear axle. Then I went inside a pre-existing hole in the frame and ran it to the back. Then I drilled a hole in the trunk floor and went up and in. Keep in mind too that I used 0 gauge so 4 gauge will be easy as hell to do.
For the RCAs, I ran them to the passenger side under the dash. I then pulled all the trim for the door sills. You can feed the line under the carpet and reinstall the trim and you own't even see it. When you get to the rear, feed it through the edge where the rear seat back installs. It's an invisible install when you're done.