For those that already have in mind an automotive application for the Arduino Due and the almost ready for release CAN API, while it seems to be too early, I believe is timely for them to start seeking out as much information as possible of the CAN protocol of their vehicles and get familiar with it. For example, the specific type of CAN standard and some specifications like CAN identifiers, Bit rate, message type (default 11-bit identifier?), data format, range definition, etc... I must say, during some tests, often, I had to stop my test and spend a considerable amount of time searching for needed CAN info. Oh, I forgot: try to get an OBD-II male connector (plug) and where is the OBD-II connector located in your car (Most are located under the steering column).