I've seen worse. Much worse. My first car, an 83 chevy pickup, had a clothes-pin holding the ground wire to a metal part on the dash board that had the paint scratched off of it with the key. The speakers were held down with electrical tape and were run parralel off of one wire of the headunit. The rest of the wires were left bare and dangling behind the dash, twisted together when they had to be, no electrical tape or fasteners to speak of.
My grandfathers 87 VW Fox's headunit (and most everything else) was wired completely with copper house wire. It took me three days to straighten that **** out.
A friend of mine picked up a Buick from a junkyard and turned it into his daily driver. Someone made an accidental pass with a blowtorch or something and melted most of the plastic covers off of the headunit wires, so when you would hit a bump all sorts of sparks and cool stuff would happen. Luckily all it needed was a new wire harness.
A friend of mine had boasted for quite some time that he had 2 12's. So one day I went over to listen to them. I ended up staying there for almost 8 hours fixing a rat's nest of wires and disconned and blown amps. I got almost three pounds of wire that wasn't even hooked up to anything, and... i think you get the picture.
Yea, a clean install is hard to find in my area. ALthough I shouldn't be talking, with my alligator clip remote wire...