Aux input cable in glove box

[Kidsbelly]

Hi all.

Recently bought an A5 coupe (2013).  Previous owner left the aux input cable connected in the glove box, but when I try to use it I get nothing.

It's not listed as an option in the media section of the MMI 3G.

I've tried to get into the "secret green menu" by pressing "car" and "set up" buttons at same time, but nothing happens.

So now I'm at a loss!

Any help greatly appreciated!

Thanks