This doesn't affect me, I just found it while testing mods. If you drive a Railway Motor Car through a Train Tunnel, the teleportation breaks the link between you and the motor car. You can exit it, and it stays on the track like a normal locomotive, only you can't mine it. If you're interested in adding compatibility, it will need code in one or both mods to make it work.

Thanks for the report. It was caused by the Train Tunnel-Mod because it destroys and creates the trains instead of teleporting them, thus breaking the link.
But I fixed it on my side, making my mod more robust (hopefully).

Thanks! Might I suggest a further compatibility feature, where if a player does enter a railway-motor-car-train that wasn't previously registered (perhaps it was teleported or placed with the editor), that it becomes registered to the player's equipment like normal?

Thanks for the suggestion, added the binding with version 0.2.2