I wonder whether it would be possible to route the CAN traffic coming in via the OBDII port of the M2 through to the 26-pin GP connector on the other side. I could connect a ELM327 adapter without a Y adapter (splitter) to that GP connector. If that would be possible, would that interfere with the M2RET for SavvyCAN?
If you look at the documentation that is available you would find out that the connector opposite the OBDII port has other features that are completely different than OBDII. Theoretically you could connect a second M2 and with custom changes to the software you could send the data from one M2 to the other but this is not something that is in the current software. The connector has a serial output which could be connected to another M2 and they could talk that way. But getting a Y cable would be very cheap and less time consuming.