So I came up with this idea to install a small flashing red alarm LED in both mirrors. I would have to drill a hole so that I could flush mount them from behind and run the wiring into the car. How would someone drill a small hole in them without they cracking or spiderwebbing? Is there even a way to do it or is it next to impossible. Sure someone has been able to drill a hole in glass or a mirror before.

 

Why would you drill a hole in the glass? If they are power mirrors there is already wiring, use the stock wire locations. All you would have to do is remove the reflective coating from one spot on the back, MAYBE. Test your LED in a dark room, and see if it doesn't shine through the mirroring on the back of the glass. If it doesn't, see how it looks when you shine the LED into the side of the glass, or maybe even consider lighting up the inside of the mirror housing so it flashes around the outside of the glass.



If you have to drill into glass, you will certainly find a video of how to do it on youtube.

 

why not just mount it behind the mirror, so it flashes in the mirror housing? not an individual LED effect but still a flashing light

 

always score a small circle.. So if it cracks it wont spread outside the whole.

 

Get a glass drill bit and follow these instructions.





How to Drill a Hole in Glass

 

Diamond lapping compound, and brass round stock of the same diameter as the needed hole.



Use a drill press and change the lapping compound out as needed.



If my memory serves, there are 2 unused locations in the power mirror connectors, and possibly the door pass-through connectors, and you can get the needed pins with wire from junkyard harnesses to run them through the door jam.



If you're gun-ho on doing an in-glass install, I'd say best bet is to wet-grind halfway into the glass, then use optically clear epoxy to bond the LED in.



Try doing the edge-light and back-light ways as well, they may end up looking better.