I removed the homelink board with its buttons since it was too old on my 99 to run my rolling code garage opener. I ran my Pioneer DMH mic up the passenger side A-pillar and under the headliner, then clipped it where the homelink guts used to live. The holes the homelink buttons used to poke through are now empty and allow audio from the cabin to get to the mic. Someday when I get inspired I might put some speaker cloth over the holes, but even without it's completely hidden and seems to work fairly well.
I did this while I had my headliner down to fix my sunroof, but I think you could just remove both a pillar trims and the visors and drop the front down enough to fish it through without too much hassle.
I did this while I had my headliner down to fix my sunroof, but I think you could just remove both a pillar trims and the visors and drop the front down enough to fish it through without too much hassle.