A little more progress.

After fixing the disaster that was my former radio wiring this was the mess I needed to get under the carpet.
The original wiring wasn't
that bad, but I try not to use electrical tape for anything anymore. At least most of the connections were soldered.

Now all connections are soldered and shrink-wrapped.
After sorting and pushing it into loom.
Then I became ambitious. I decided I really did not want the wiring showing up as a lump in the carpet, and wanted more temperature insulation and sound deadening in the floorboards. So I pulled the carpet back out, and picked up some heating duct foil-backed insulation from Lowes to line the floorboards.
Where the wiring runs there is no insulation, so most of the thickness of the wiring is "masked". I think after the carpet (and it's insulation backing) is reinstalled, you won't even be able to see or feel the stereo wiring unless you know where it is.
Last thing I accomplished tonight was mocking up the mounts for my stereo amplifiers.
Both amps I acquired used (thanks Greg!

), but the price was right. The blue amp will be bridged for the subs at 400 W x 1 (RMS), the silver amp is 50 W x 2 (RMS) for the door speakers. The pioneer 6x9 door speakers have really been underpowered by the head unit, until now. ;D The stereo won't be winning any competitions, but should sound good, and should now be able to easily mask the noisy flowmaster drone of my true-dual slant running down the highway.
I made some 3/4" steel spacers from a scrap piece of tube I had laying around, so the amps would be raised off the carpet to aid in cooling. Here is the blue amp mocked up, without the carpet.
With any luck, tomorrow I will have the carpet reinstalled, the stereo finished, and the seat & seatbelts re-installed. Chuggin along....
-S/6
P.S. I can already hear Dan grumbling about booming stereos from us 'young whipper-snappers'.

Don't worry Dan, this is not the stereo that you hear rattling every car at an intersection and rattling windows rolling through residential neighborhoods. I don't listen to it that loud, but I like to hear the full range of tones from my music.

The head unit alone does not have the power to accomplish that in my truck. I
hate tinny (aka sounds like a tin can) treble and non-existant or 'poppy' bass.