hey, i never said i use it for beating on drivers! just for knocking on their cars!

anyway, carabiners that large can be purchased at outdoor supply stores. you're going to want one that's large, made for climbing, unless you have tiny little paws. if you have big meaty hands, you're going to need something more than a carabiner keychain.

anyway, my brain also says that escalation/retaliation sucks.