The VE Series I Sat Nav unit does broadcast a bit of information over the SWCan via the NIM Gateway module.
(The NIM Gateway module basically connects to the Blaupunkt BUS, and interfaces with this BUS using the SWCan Bus.
Typically this is used for,
1) Sending some of the headunit button and knob data to the Navigation Unit when in Navigation mode.
2) Sending Text and icon data to the Instrument Cluster (For Street Names, directions and distance info)
3) Sending the current GPS time from the Nav unit to the Headunit for time synchronization.
There is some information on this in the GMLan Bible (An excellent source of SWCan information).https://docs.google.com/spreadsheet/ccc ... MXc#gid=24
On a side note, I recently tried the Carberry shield for the raspberry Pi.
On paper this shield looked very promising (2 SWCan Bus lines, and 2 OBD Lines), plus lots and lots of other Lines for various things, however I have to say the shield has been a bit of a disappointment.
The SWCan Lines are not programmable (They will interpret a tiny subset of the SWCan 29 Bit data, mainly steering wheel control data), and the firmware for the drivers on these things is closed source - non expandable.
Also documentation on this thing is severely lacking, to the point where I would honestly say it is around 20% complete.
The manufacturers of the thing have promised updates and improvements in the documentation, but I have noticed nothing new since late July 2014.
If anyone is interested, have a look at the following link.http://www.carberry.it