I rotated my tires today and heard something fall from the front-end of the car somewhere while I was jacking up the car. I didn't think anything of it until I was sweeping up after and found this metal snap ring. Because I found it after and wasn't paying attention, I'm not even 100% sure which car it fell from! It could've been from either a 2013 Volvo XC60 (non-turbo) or a 2013 Toyota Sienna XLE 3.5L. Does anyone know what this thing is?
What it is is a snap ring. I have no clue where it would have fallen off of, so your guess is as good as mine. Snap rings are usually enclosed within places, like to hold bearings in place. It would not have fallen off due to rotating your tires alone.
EDIT: Looking closer at the image you provided, it looks to me to be an unused snap ring. I see no evidence of any type of wear on it or tool marks where you'd normally see them if it's been put in place somewhere for use.