I was cleaning out the map pocket in the passenger door and found this in the bottom. It's clearly some sort of test plug, as it has loopback wires. But beyond that, I have no idea where it came from, how long it's been there or what it is.
The part number on it is BMW 1378121. It's 1.5 inches wide by 1.25 inches long.
Anyone have good guesses or even identification?
