Hey I just bought a 2005 350z a few weeks ago.

When I removed the interior door panel I saw a connector that's not connected and this is on both sides.

 

I looked at the pg.pdf section of the service manual and I believe the white connectors are for the power mirrors and the brown connectors are for the tweeters. It's easy to check. Do your power mirrors work and do you get sound from the tweeters?

 

Sorry I meant this connector

 

My mistake. However, your picture is no longer shown on this thread, so I can't see which connector you're talking about.

 

 

I'm not sure, but I think the connector in your picture is the item I've circled on the attached page from the Service Manual. It appears to be a capped-off connector with electrical tape holding the cap. Unfortunately, the item circled in the Service Manual isn't identified by a connector number.

 

There are unused wires and connectors all over the car. I would be for a power folding minor option we done have