Ban the concrete blocks!
Don't tempt a good boy to go bad.
You remind me of a story I posted here years ago: A teenaged boy and some buddies stole a car and went joy riding. They smashed into road signs and mailboxes and eventually ripped up the tires by crashing into elevated curbs. He ended up driving the wreck back to his own house on a couple of the wheel rims. The cops tracked him down simply by following the grooves he dug in the street all the way home. The mother was quoted in the newspaper defending her son as a "good boy." For his part, the boy said "I wish I had never seen that car!" That's right-- the car was responsible!