Glad I found this thread. Ordered the parts though ECS tuning, cheapest I've found with no handling fees. Dealership wanted $60+ for one cable.
Going to have this done to my 2006 BMW 325XI "basic" without logic7, etc... I have a kenwood headunit and the only problem I've had is the SOS error. The SOS does work, I pressed the button and did get someone on the other line and they could hear me just fine.
Any reason this is all the way in the trunk? I'll probably stash it in the glove box or something.
Will a constant power line from the battery cause an issue? I know my BMW is sensitive to parasitic power loss and then in return causes a check engine light error.
I'd rather find an auxiliary accessory line so the power cycles off with the car when it turns off, instead of a constant power source, thoughts?