For usb charging you need to have radio option io4,io5 or io6 (because they are the only option that have a HMI behind the lower glove box) then you need to plug a mini usb male inside the usb socket until the HMI with the other side of cable that it is also a mini usb male
This cable can be done with 2 cable (cut and sold them togheter)
Or be bought but the only place I found some was on ebay and hard to find
Hope this will help for usb charging. And don't forget you need a usb cable AND connecting also pin 4 and 6 to ground and Positif voltage