Hello all, I am upgrading door speakers in my 2013 smart. I was wanting to install after market speakers and I am stumped on the factory speaker wiring. On the driver side it's two green wires with one having a brown stripe. On the passenger side it's two grey wires with one having a white stripe and the other black. You would think the brown striped and the black striped ones are the negative but they are opposite to each other on the harness. I am kinda stumped so any help is welcome. Thank you.