I have just fitted lights to my windshield hinges and i am in the process of wiring them and i intend to run the wires through some black truck fuel tube and tilt my windshield forward and put the tube between the windshield surround and the top edge of the body where there is a 2 inch oval hole and put the pipe into that to bring it down behind the dashboard, well that is the plan and if that does not work i will leave out one of the bolts on the hinge and push the tube through that and put some silicon into the hole with the tube and bring it out behind the dash.
I ran my power wires threw the fire wall to my switch and from my switch under the dash then up the side of the dash then out to the windshield mounts by just going out the door jam with some black plastic tubing
I went thru the firewall thru a grommeted hole i drilled. The drilled 2 more holes in the middle of the lower hinges. Used some fuel line or vacum line to run the the holes. Ran the wires thru that and siliconed the crap out of it.
I ran my wire behind the bracket. Then through the windscreen frame down into a hole I drilled through the fire wall. I hate wires! I wanted them out of the way. I am going to redo mine when I buy a new windscreen frame and rout all wires through the firewall and not in the engine bay to my fuse block.