I have an Elegance from 2012, with the Aux in the jumbo box. I previously removed my Columbus, and replaced it with an Android Unit, but the Android Unit was faulty, and I had to put the Columbus back. I am not pleased with the Columbus, as it is deadly slow, and as I have the Fiscon + buetooth, I cant really control A2DP from it anyway, in a pleasing manner. I almost always listen to net radio or pod casts, so I need a better connection. I have mounted an iPad mini in with a CD tray mount, but I need a bluetooth receiver in the aux slot on the arm rest. I already have one, but it's got a 4 hour battery life, so I'd like to charge it in the box, and therefore I'd like to install a usb plug in there. 

 Ideally I'd like to take the power from the fuse box for the usb plug, and also for a usb cable to the iPad. Has anybody done this, and now what I need to get to maeke this happen

There is the 12v power socket going to the rear of the jumbo box you could tap into that for the usb power 

I have used these for my Dashcam
Also can be fitted just below the Aux socket