I googled Huracan dome lights and they seem to look the same for coupes and spyders. So am willing to be you can tug it out from the front and check. Once it’s out you might be able to see into the headliner a bit and get the cable right, maybe even find a spot to put a plastic zip tie and get it fully taught?Nice write and has me thinking I should try this way. Do you think would be same for coupe? I hard wired my new car the other day and didnt need to remove panels and was able to tuck, but found its not tight enough along headliner so wire keeps dropping. Guess I can take off my dome light and see if it similar? Or would going to mirror be better?
Another thought is trying to thicken the cable at the spot it keeps getting loose at. Maybe a bit more girth will do the trick (that’s what she said..)