Hey guys so I am in the process of installing some roof lights of my 06 4cyl outback. So far the easy part has been finding the unused plug next to the steering column because I have the auto transmission. Mounting a switch and making up a bracket for my lights. But know i'm drawing a blank as to how to get the wire from the engine bay to the roof for the lights. I don't want to drill into my roof. I have seen other run their wire out the hood and silicon it into the crack where the windshield is. Has anyone done this? Any ideas would be great!

Running it through the firewall, up through the A pillar and out through the roof is the simplest and most effective way I can think of. Drilling is required for that, but you can achieve a seal easily with a rubber grommet if that is your concern.

Otherwise, I would feed the wire through some weatherstripping around the door (the flexible stuff is hollow) and wire it to the battery via the route the window motor wires follow. Would be a pain, and I'd drill, but that's one option at least.

As for the silicone method- that would work, but it takes time to cure and harden a bit. Before that, the wire won't have any anchor. Exposure to UV and other elements means likely replacing the silicone every 3 months. Hope this helps a little, I used silicone for similar purposes and found it wears quickly in those conditions.

On a few vehicles, I've tucked it behind the interior trim on the b-pillar up to the roof line, and pinch it in with the weatherstripping around the door:

How bad would the wear and tear be though if I go through the door weather striping? Wouldn't the wire fray and get damaged over time?

Probably eventually. I've done it for years. The CB radio antenna cable pictured made it onto a few different cars. You could do the exact same thing but go through the back door opening. That would probably drastically reduce the use.