"...I was immediately transported back to my childhood, when a neighbor strung barbed wire across our bike path."
My older brother tells the story of him and his friends rigging up a device to get a car that was crossing a friend's yard (corner lot). They filled two cans with cement with a wire between them. Propped them up on sticks at door height where the guy would drive. The car would snag the wire and the cans would come flying into the door panels.
Not sure if it actually worked. And it sounds like a good idea - until a motorcycle or sports car comes through and you hit the people in the head with the cans. Or - the guy with the dinged door panels stops and throws rocks through all of your windows.
Kids will be kids. (Stupid and hopefully VERY lucky.) I wonder if this plastic wasn't put up to catch a car (more likely that a car would be on the road). The kids are back in the woods to laugh at the driver's shock and then his efforts to get the wrap off his car. Not thinking about a motorcycle - or a paniced driver careening off the road.
And yes - even though "kids will be kids" (not thinking is the key phrase) they should get punished severely.
A piece of random looking debris, with a vertical part to catch a bumper will make an amazing amount of noise as it cartwheels under a car...
I was also transported back to my childhood... as a little kid, we had a corner lot on an old rural road, and I used to build snowmen in my yard as most kids do. However, a couple of teenage punks would come tearing down the road at night and cut across our lawn and run over my snowmen... So, one day I built my snowman around a fire hydrant, completely hiding it...
Let's just say that their habit of cutting across our yard came to an abrupt halt that night...