That's what it sounds like, kids with a lot of time on their hands. I'm wondering if some of that dog poop wasn't placed on the door handles of that suv...
There aren't many kids in my neighborhood, most of them are under 10. There is a couple of teenagers around 14-16, but not four of them. Wasn't my immediate neighbors who did this, it's the people who live down the street, roughly 5-6 homes away. They have their own click of 5-6 homes where they hang out on the weekends all the time. My neighbor that moved out told me what they "think" about some of the people in the neighborhood and I didn't care for it. Invited me to join their click a few times, but I didn't have the time nor did I care to hang out with Cowboy fans.
It sounds like we still have a missing bag of grass clippings. Maybe grass clippings in the tail pipe trick?