I Think I Just Saw a Mannequin Head in the Back Window of That Car

Look what I spotted in the parking lot of Crossroads Mall in Waterloo, Iowa! Clearly there is a mannequin head in the back window of this car next to two silver pom poms. That's...not normal.

My Main Question

Was the head thoughtlessly tossed in the back window or was it purposely displayed there?

My Next Question

How common is it to place a mannequin head in your back window?

 

My Third Question

What other weird things do people put in their back windows?

 

I googled images of "weird things in the back window" in order to find some other funny pictures to share. This was the second image, and is the only image that had ANYTHING to do with "weird things in the back window."

It appears to have been taken in New Jersey in September 2012. It's definitely a different mannequin head in a different car. I couldn't find any other photos or references to mannequin heads in the back window, so maybe it was just a weird coincidence. I'm quite baffled!

P.S. Please let me know if you have an extra mannequin head. I want one awfully badly.
P.P.S. I think these are cosmetology practice heads. Still...why are they being stored in people's back windows?