Ok, found it: Pioneer AVIC U310BT - Page 4 - Tacoma World Forums, the caption says, "I drilled a hole a little bigger than the mic diameter, then inserted a rubber gromet (the kind of gromets used to pass wires trough the firewall) then pushed the mic from inside out (takes some time and patience to get it right). Makes it look factory and had no problem with the location, everyone hears me clearly and most were unable to tell I was speaking from a mic. They can hear me clearly even from the passenger seat" - member epa4wd.
This was fabricated, not purchased. Looks like a factory part! Great job, I may do this as well for my mic (whenever I get around to it).