Fun stuff! The dash panel color scheme reminds me of my old Speak & Spell. Something that made feeding wires go much more smoothly for me was feeding a length of fairly stiff nylon tubing (from the local hardware store) to use as a flexible conduit. It was especially good for a run that passes through multiple spaces with sharp metal edges. I ran one up the B-pillar of the Ranger to the rear of the cab and was able to feed rear speaker wires through it with ease and zero snags.
