I have a dash cam and I need to thread the cable under the glove compartment, up the passenger side window, and over the roof to the rearview mirror, to connect to the dash cam that will be clipped there. I don’t know the best way to do this, or if there are clips I can buy?
The correct way to do it is to remove the A pillar trim and drop the headliner in front, then lay the wire behind them and re-attach them.
The cheater way to do it is to cram it underneath the A pillar trim and headliner while they’re still attached.
Which method you use will depend on how thick the wire is - if it’s too big you’re gonna have to drop the trim to get it under there.
Is the power cord even long enough to reach that route you plan? Second, if you are planning to leave it attached to the windshield that is an invite for theft. Which will cause more damage than the cost of the camera.
that’s the way I wired my cam. Works like a charm.
You could probably benefit by finding an “exploded view” drawing of the interior and getting some nylon interior paneling tools like the ones in the link.
Is there a lighted vanity mirror on the passenger side visor? If so current is available as is a convenient ground connection.
Shadowfax has the answer. I used cheater’s way. Its darn easy and obscure. Did it once and thats it, no more hassles. Check youtube, there are a lot of videos.
More important question is, how are you going to attach the dashcam to the windshield. I live in NY and it has been a nightmare. I was suggested 3M tape. I tried every possible combination of attaching 3M tape and then hanging dashcam to it but every summer, it has fallen.
In the OP’s other thread they state they have decided to return the dashcam.
Mine uses a suction cup and has stuck on the windshield ever since I stuck it there. The key is to have the area absolutely clean and the suction cup slightly moist (give it a good lick 
) when sticking it to the windshield. The other option is velcro.