It's a cut-down internet service - basically lets you get certain sites (google et al) via the in-built SIM. It also means you can do routes in google maps and then get them sent to your satnav. Doesn't work when the car is in motion though - so no porn on the move.
It should come with the instructions, but this is what I was told came on my Z4MC - it was only after days of trying to get it working that they told me I had a cut down version which didn't do 90% of the things they claimed.
