Wow great information from everyone. I have a 2008 135i. The trunk and everything is still torn apart and I did some digging today with more pictures. The car is really messy, I'll be giving it a deep vacuum and clean since the previous owner through garbage under the passenger seat...
There is a harness in the trunk with the part #1-1355084-2e
There are 4 wires also in the trunk that are cut. There's a black harness with what looks like 4 smaller wires inside of it. There is a single blue wire, and there is a dual-blue wire.
The set of wires go under the passenger seat and floorboard towards the driver-side seat. Once they get to the driver seat, the dual-blue wires go underneath seat to who knows where.
The black wire, along with single blue wire go all the way up towards the trunk release/hood latch.
Pictures are a bit out of order. The harness with part number listed above goes into the wheelwheel somewhere. After looking around some state it is for an amp/radio harness. What is it doing in the trunk? I'm curious that whoever had this car before me messed around with the audio system quite a bit. Maybe even upgraded the stereo from the base equipment it had.
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