I haven't done this myself, but I have run wires to similar places.

I have audio and control cables run from the Head Unit out to the area above the passenger's feet for my FRS radio's integration into the car's sound system as well as wiring from my electronic oil pressure gauge above my right foot out to the engine compartment.

I also have wires run from the shift console-area to the engine compartment for my fan override switch [which I don't use anymore, as I have the -10C fan mod] and my EGR cutoff switch. These wires run from the area of the window switches, around the left side of the heater controls/radio column then above the pedals over to the afor-mentioned passage into the engine fuse box. All wires are hidden under the plastic panels of the car's interior. The area around the steering column is a problem, the shaft is uncovered and moves with the wheel, so be sure to keep wires tied up and out of it's way!!!


Here is my suggestion:

Clip the mic to the sun visor. Run the wire over to the side of the windsheild, tuck it under the trim piece and run it down the side.
Remove the fuse panel door and run it in there, put the fuse door back on.
Remove the panel from above the pedals (not hard, I think it's just two screws) and run the wire thru there, taking care to tie it down around the steering column.
Remove the head unit and use a speedo cable/ CB radio antenna rod / etc. to snake thru to the underdash area.
Tape the cable to the speedo cable and pull the speedo cable/etc. with the taped-on wire into the back of the head unit area.




Don't be afraid to pull some screws out and look around! There are passages you can use all over the place.