The microphone is to detect the sound of glass breaking - mine is installed in the location you mentioned, by the shifter.
I guess this is the best location to pick up on any of the glass being broken. Maybe if it were on the steering column it wouldn't be able to detect the passenger side easily?
I guess this is the best location to pick up on any of the glass being broken. Maybe if it were on the steering column it wouldn't be able to detect the passenger side easily?