I suspect your problem is that a D3 needs a canbus-capable interface, which a KEY-USB is not:
Your best bet is to sell that to someone with an earlier K-line model (it would probably work fine on a D2 or something of similar vintage) and then either look out for a used HEX-CAN, or buy a new HEX-V2.
Edit - like this one for sale on the forum here:
http://forum.a8parts.co.uk/showthread.php?p=155022