I keep mine in the slot to the right of the shifter and just have the cable coming out of the astray (insert removed). If you're using the grom simple input (aka 3.5mm input) then I'd suggest somewhere around there so you can easily reach the player to switch songs. If you're using the ipod version then your options are more open since you'll be able to skip songs, etc. so you could put it in the glove compt. or center console.