The chrome piece should be behind the dash. But someone had chopped up the corners on my dash. Not a full DIN cutout, but enough that it looks terrible with the chrome nosepiece poking though. I ended up painting the "wings" flat black and putting it in front. Wasn't that difficult to set nuts along the shafts to get things in the places they needed to be. Unfortunately, there isn't an insert in the '66 that could be replaced. I think you'd have to redo the entire sheet metal.