I went with this guy:
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

and it works well. i have it plugged into the cigarette lighter in the arm rest and the button/cable coming out the front of the box and stuck right there.

I searched for awhile to find one that could power on by itself when the car started. Not many do this, but this unit does. All i generally need to do is hit the button and music starts playing as long as my iphone decides it wants to :). This is basically as good as the Audiovox (Dice mediabridge) install i have in my 330 which feels more factory, but with a lot less pain to install than that was.