UPDATE: I threw this photo around some other forums/blogs, and this is what I read.
One of the replies in the discussion said it was for real-world noise, vibration, and harshness testing. That muffler strapped to the back of the car eliminates as much exhaust note as possible so other noises aren’t drowned out.
That explains why it is so temporary looking, and looks like it can be strapped to just about anything.
I have no idea what is going on here. - Discuss.