It's the wire that the red arrow is pointing to in the pic.

I put some sound dampening sheets on my trunk lid and can't find anything to reconnect this wire to. I don't remember there being an unconnected wire when I first opened it up. The wire from the right side connects up to the two connectors by the latch and there's no other connectors. I feel like an idiot. What am I missing here???

 

Third brake light for the oem wing.Comes prewired with or without wing

 

...or is it the emergency trunk lid opener if someone gets stuck in the trunk??

 

This is what I'm thinking it is. I've got the wing but haven't tested the third brake light. I know that my rear lights and brake lights work. The question is, where is it supposed to hook up to?

 

Nope, that's the thin cable running to the left of it. I've got that hooked up. It's definitely a wire that's running power to something. It's got a harness on the end.

 

I found it. Duh! As soon as I looked at it today I saw the connector in the wires right above it. Guess I was just too tired last night.

The wire was for the third brake light. caskyline, you were correct! Thanks!