Good point about the single din. You're right, without a centre console, there isn't much space for anything you want within arms reach.

You could consider halfway up the the a-pillar. Or maybe mount it in the corner of the pocket of the dash kit? (Run the wiring through a drilled hole in the back. As long as there's still enough room for wallet, etc?) It's to pick up your voice, so I guess keeping it down away from the roof would be the best.