I love this thing.
It’s a piece of scrap – a 3/4-inch-thick slug of aluminum sliced off the end of a 13-inch-diameter aluminum cylinder.
Whack it, ed and it rings for more than a minute, physician with an intense, Döpplering tone.
I’m going to mount it on the front, and maybe I can hook it up to a simple solenoid so it can be rung from the driver’s seat.