I have these blank buttons in front of the gear shift in my car. They don't do anything except take up space.
But I found this guy who makes custom buttons like this eject button. So I'm going to install a garage door opener directly into my car, and this is the button that's going to make it work.
The rest is miscellaneous wires and fasteners. I'm not wiring the garage remote into the car's electrical system. It will still be battery powered. If I get tired of changing one battery every few years, I may change that.
Modding the Remote
I think it will make everything a little more professional if the garage door remote is removable and not ruined by this process. So I'll install an external connector on it that the switch wires plug into. That way I can unplug it and remove it to replace the battery or loan to visiting family or whatever.
I drilled a hole in the housing to take a panel mount jack.
Then I soldered in the jack.
For now, I'll just leave it velcroed inside the console. If it actually makes noise or bugs me, I'll hold it in place somehow.
Taking The Dash Apart
To get everything apart, I did a little Googlin' and found how to get it this far.
I installed the switch according to the included instructions (translation from the original German courtesy of Google Translate).
It operates the garage door and lights up when the headlights are on!