Electrical Enclosure

I believe it guards the positive battery post on your 12 volt aux battery which is immediately in front of the passenger tail light. Take a look there for exposed battery post.

 

I don't want to guess what happened, but one could assume either they bumped something around your tail light and tried to fix it or did not understand how to turn off power and just disconnected battery.

 

Betcha they had to jump start your car.

 

Yeah, what has happened...has happened.
But if I found that in my car after having it Valet parked, I'd be a little upset.

That isn't a part that would just "accidentally" end up in your hatch area.
That's a part that has to be consciously removed, and probably does mean somebody was trying to do "something" with your aux batttery. And if they were trying to jump it? I'd hope they did it right, and I'd be mad they didn't tell me or ask first.

 

I'd be furious.
1) It is very bad for the 12v battery to be fully drained. Test the battery.
2)That red cover my have been/broken snapped off. I'd check that, too.

 

welcome to priuschat! avoid valet's like the plague, if at all possible. all the best.

 

Actually, unplugging that fuse may be a safer way to charge the 12v battery.

JeffD