Is this the fiber optic cable for my disc changer hookup for a 1999 e300td? It appears to be a large orange wire wrapped in black cloth insulation, and I located it behind the wheel well paneling on the drivers side in the trunk. Thanks to anyone who can help me identify this. And if so, does the plug i'm holding in my hand just plug into the disc changer and it will work, or is there more to it than that? Thanks.

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2006 E320CDI- current dd
1999 E300TD - retired
Wilmington, NC USA