Hello, M3 Fighter Pilots!!
My M3 friend (6MT) has succeeded to install Shift Indicator, using the information of my site.
In Japan, some products are sold as follows.
This is DIGITAL type, like BMW Performance Steering LED.
This is ANALOG type.
These Shift Indicator is made by Pivot
, and model list is here
The Tacho Signal (Engine Spark Pulse Signal) can get form OBD-II Port.
Pin 9 is "Tacho Signal" and pin 4 or pin 5 is "Earth" (Signal Ground).
Some information about "Tacho Signal" (OBD-II Port) see here
(Sorry, This site is written in Japanese.)