Its neither
This is a fully wired interface box, it has 3 wires and a power connection.
I was in my local Car electronics store a few months ago and they had a 350 in doing a full install, and they were telling me they were liasing with a company in the UK developing the interface box .
So I went in yesterday and asked them , and they had cracked it, and had 1 left , so I had it,
If you speak to them they may be able to get more ( as all the r&d is done now )
It cost me £50
Steve