Hi,
I'd like your help because I'm new in the story with Arduino ... 
It is the Alfa GT in which I installed the 2.4 JTD engine that does not have CAN BUS communication with the dashboard.
So you need to send a signal of temperature and RPM via the CAN line to dashboard.
What should I do?
I ordered: MCP2515 CAN-BUS Shield Controller with SPI Interface & MCP2551 CAN Transceiver.
Is that enough or do I need more?
Thank you very much for your help and excuse my bad English ..