What is this?
 

Anybody know what this is?

Not a clue.
On a motorbike it might be a fancy battery hold down clamp

I give up. What is it? Where'd you find it?

What is this?
 

I found in in the bin beside the spare tire well, but I can't remember if it was in my '06 xA or my '06 xB.

it's a bungie type of cord used to hold down the jack in the plastic bin. There is a place to hook the rubber piece on the bottom, and a hole on the wall opposite that to place the hook