The Blue & Me takes up the AUX socket on the head unit. It's possible to combine the B&M signal and the signal from your phone/iphone by creating a simple resistive combiner and connecting the two leads together whilst playing a silent audio track on your B&M. I wrote a guide for part of this, but for some reason it's not letting me edit it to put the bit about the resistors in. So I'm trying to edit that atm.
This is the guide: https://www.fiatforum.com/ice-guides/310168-aux-blue-me.html
However you need to put some resistors in, but it's not letting me edit it :/ I've attached an image of the circuit diagram you'll need. Hopefully with the guide and this image you'll be able to work it out. I've found that it works pretty well And it shouldn't take you too long. Ask me if anythings unclear.
I also put a fitted aux socket by the cup holders. When I went to write up a guide I'd found there was already one there. But you can see pictures of mine in the comments: https://www.fiatforum.com/grande-punto-guides/273950-fitted-aux-input.html
I'd definitely recommend using one of the screw together sockets like Cadebena and I used instead of super gluing one below the plastic like in the guide. It looks pretty professional when finished.
Edit: Doing it this way also means you don't need to spend £17 on an aux cable it should cost you about £5 over all.
Does it matter that when I double press CD it never says AUX or when I press the SRC on my steering wheel that never says AUX either?
That doesn't matter because you'll be playing a silent audio track through the blue and me. So it will show as though the 'Media Player' is playing. And on your screen behind the steering wheel it will say whatever the name of the silent track is. But you'll be able to hear what's going in though the aux
If you want, you can play one song through the media player, and one through the aux input at the same time.
I don't even know how to play music through blue&me, is that using the USB stick? And do I use the usb that has the windows sticker next to it?