Screw McDonalds

So a couple of days ago I picked up some McD's food on the way home from work.
When I had almost finished my salad, I saw something glimmering at the bottom of the bowl:



What kind of treause could this be? A prize?
After some further searching, this was what I found:



Two bolts. Somehow I doubt that two well-worn screws are part of the normal makeup of a side salad!
But maybe I'm overreacting, perhaps it is some new kind of marketing ploy, where you get the pieces one by one and have to assemble it later. I wonder what could be hiding the next time I eat a Big Mac, a couple of tires perhaps?

If only I had lived in the US, then I could have claimed that I bit into one, hurt my teeth and then sued McDonalds for about five gazillion dollars...