The HDD is simple, it's just the USB adapter for the AMI and a 2.5" HDD that's powered from the USB adapter, mine happens to be Audi branded, but any drive will do.
The USB sockets I don't think I ever got a proper write up done. It's a really simple mod to do.
- Remove the central cubby, which does need some fiddling with the armrests too to get it out.
- Take the rear climate panel out, the lighter surround pops off, and thenit's two torx screws and it pulls out from the bottom.
- Fit a lighter to USB adapter in parallel with the rear adapter.
- Fit a flush USB socket such as
http://www.maplin.co.uk/neutrik-usb-...-socket-219901 . You'll need to cut the appropriate sized hole, be careful you don't damage the coloured coating.
- And then just connect a USB cable from the charger to the socket and the on to your device.