MCP2515 CAN-bus module (with 10+ analog inputs and some digital IO internally) for serial AIM stream => CAN bus data conversion (often to CAN-dashboard).
v3 ECU firmware mods NOT needed (all the required signals are sent via AIM-stream, 1st or 2nd RS232, 2nd is more practical).
New module is smaller form factor and 5V analog inputs (more IO), with different processor, and FW upgrade supported (but should NOT be needed, and requires some patience).
Old module had STM32F103 and 3.3V analog inputs (fw upgraded not supported).
Depending on the CAN-ids and format required by the dash, specification of exact CAN-IDs might be needed, see
CanBus wiki page
and
pinout
Configured to CAN_VARIANT_BMW_E46_M54_S54 by default. Choose model, eg CAN_VARIANT_VAG_2001_A4_AWM_18T 
