I have mine laying loose in the glove box. I don't have a ashtray, so I can't fit it there.
I've thought about fitting it in the rear center console, where the IN/OUT stuff is located on cars with the TV option. (Like this
http://finncdn.no/mmo/2013/12/vertic...4481597_xl.jpg ) But that would require a long AUX-cable.
How about cutting out a little piece of the coin holder in the armrest, and placing it there? What do you guys think about that? That way it stays hidden when you want to hide it. I have a pretty thin AUX-cable, so it would be no problem closing the armrest with the cable sticking out.